Robot for handling

ABSTRACT

A handling robot comprises a first and a second robotic link mechanism (B 1,  B 2 ) so configured as to be jointly rotatable. Each mechanism has a transfer table ( 8   a,    8   b ) at its forward end and is adapted to operatively be projected and retracted in a radial direction with respect to the transfer table when operatively extended and contracted. The first and second robotic mechanisms are arranged so that the two transfer tables may located within a narrow angular range.

TECHNICAL FIELD

The present invention relates to a handling robot in a multiple chamber type manufacturing system such as a semiconductor manufacturing system and an LCD manufacturing system, in which a plurality of process chambers are disposed around a single transfer chamber to constitute a like plurality of stations, and in which a workpiece in the form of a thin plate such as a wafer that is to be machined and processed in each of the process chambers is conveyed by the handling robot that is arranged in the transfer chamber, via the transfer chamber from one of the process chambers to another.

BACKGROUND ART

A multiple chamber type semiconductor manufacturing system is constructed as shown in FIG. 1 of the drawings attached hereto and has a plurality of process chamber stations 2 a, 2 b, 2 c, 2 d and 2 e disposed around a transfer chamber 1 and also has arranged therein a pair of workpiece delivery stations 3 by each of which the workpiece is delivered to an outside thereof, and in which the space within the transfer chamber 1 is kept in an evacuated state by a suction unit.

And, the above mentioned transfer chamber 1 is constructed as shown in FIG. 2 of the drawings attached hereto and has a handling robot A provided at a central region thereof so as to be rotatable. It is also provided with a plurality of partition walls 5 that serve as the peripheral walls thereof with each wall opposing to each of the process chamber stations 2 a, 2 b, 2 c, 2 d and 2 e and the workpiece delivery stations 3 and in which there are also provided a plurality of gates 6 each of which constitutes both an inlet and an outlet for the workpiece to be fed into and out of each of the stations. Each such gate 6 is configured so as to be opened and closed by an opening and closing door (not shown) that is disposed in opposition to each of the gates 6 in the transfer chamber 1.

As a conventional handling robot of this sort that has been used with a semiconductor manufacturing equipment, there has hitherto been known a handling robot A of so called flog leg type with a pair of arms as shown in FIGS. 3 to 11 of the drawings attached hereto and a handling robot A′ (see Japanese Unexamined Patent Publication No. Hei 7-227777) of identically directed operating type as shown in FIGS. 12 to 13B of the drawings attached hereto.

The above mentioned handling robot A of flog leg type with a pair of arms in the prior art is constructed as shown in FIGS. 3 to 6B.

In this construction, a boss section B is provided with the pair of arms, designated at 7 a and 7b, of an identical length, which are arranged so as to be rotatable about a center of rotation. On the other hand, there are provided a pair of transfer tables 8 a and 8 b that have their respective bases, to each of which is connected one end of each of a pair of links 9 a and 9 b of an identical length, respectively. The one end of each of the both links 9 a and 9 b is coupled via a flog leg type transfer table attitude regulating mechanism to each of the transfer tables 8 a and 8 b, respectively, so that the two links 9 a and 9 b may be rotated in a pair of mutually opposite directions which are completely symmetrical with respect to the transfer tables 8 a and 8 b. And, one of the pair of links 9 a and 9 b which are coupled to the transfer tables 8 a and 8 b is pivotally coupled to one of the pair of arms 7 a and 7 b whereas the other of the links 9 a and 9 b is pivotally coupled to the other of the arms 7 a and 7 b, respectively.

FIGS. 4A and 4B in the drawings attached hereto show the transfer table attitude regulating mechanism of the above mentioned flog leg type, in which the respective forward end portions of the links 9 a and 9 b in the pair which are coupled to the transfer tables 8 a and 8 b are coupled together in an interlocking configuration that, as shown in FIG. 4A of the drawings attached hereto, comprises a pair of gears 9 c and 9 c which mesh with each other so that the angles of attitude θ_(R) and θ_(L) of the links 9 a and 9 b with respect to the transfer tables 8 a and 8 b may always be identical to each other. This allows each of the transfer tables 8 a and 8 b to be always oriented in a radial direction and operated in the radial direction when each of the arms 7 a and 7 b is rotated. It should be noted, however, that the above mentioned interlocking configuration for the links 9 a and 9 b may make use of a crossed belting arrangement 9 d as shown in FIG. 4B of the drawings attached hereto, in lieu of the above mentioned gear arrangement.

FIG. 5 of the drawings attached hereto shows a mechanism for permitting the above mentioned arms 7 a and 7 b to be rotated independently each other. The respective bases of the arms 7 a and 7 b are each configured in the form of a ring shaped boss and such ring shaped bosses 10 a and 10 b are configured so as to be coaxial about the center of rotation and to be rotatably supported with respect to the transfer chamber 1.

On the other hand, the ring shaped bosses 10 a and 10 b have a pair of disk shaped bosses 11 a and 11 b disposed therein, respectively, wherein the ring shaped boss 10 a, 10 b and the disk shaped boss 11 a, 11 b corresponding thereto are arranged so as to be coaxial with each other. Each pair of a ring shaped boss 10 a, 10 b and a disk shaped boss 11 a, 11 b corresponding thereto are magnetically coupled with a corresponding one of magnetic couplings 12 a and 12 b, respectively.

The above mentioned pair of the disk shaped bosses 11 a and 11 b have their respective rotary shafts 13 a and 13 b which are arranged so as to be coaxial with each other. The rotary shafts 13 a and 13 b are coupled to the output sections of a pair of motor units 14 a and 14 b, respectively, which are coaxial with the frame la of the transfer chamber 1 and are supported with their positions deviated in their axial direction.

The above mentioned motor units 14 a and 14 b have each integrally coupled thereto a motor 15 which comprises, for example, an AC servo motor and a speed reduction gear 16 with a large speed reduction ratio which comprises, for example, a Harmonic Drive (trade name, identically referred to hereinafter). Such reduction gears 16 and 16 have their output sections which are coupled to the respective bases of the rotary shafts 13 a and 13 b, respectively. And, since the space within the transfer chamber 1 in which the arms 7 a and 7 b are positioned is held in an evacuated state, there is provided a sealing partition 17 each between the ring shaped boss 10 a and the disk shaped boss 11 a and between the ring shaped boss 10 b and the disk shaped boss 11 b of the present arm rotary mechanism.

FIGS. 6A and 6B show an operation of the above mentioned handling robot A. As shown in FIG. 6A, when the two arms 7 a and 7 b are located at a pair of diametrically symmetrical positions, respectively, with respect to the center of rotation, the links 9 a and 9 b will be in a state in which they assume their most expanded rotary positions with respect to each of the transfer tables 8 a and 8 b so that the latter may both be displaced toward the center of rotation.

In this state, by rotating the two arms 7 a and 7 b in an identical direction, it can be seen that the two transfer tables 8 a and 8 b will be rotated about the center of rotation whilst maintaining the radial positions thereof. Also, by rotating the two arms 7 a and 7 b in the directions in which they may approach towards each other (or in the mutually opposite directions), from the state shown in FIG. 6A, it can be seen that one of the transfer tables 8 a that is located at such a position that the angle made by the two arms 7 a and 7 b is reduced will be pushed by the links 9 a and 9 b so as to be operatively projected in its radially outward direction so that it may be thrusted into one of the above mentioned process chamber stations 2 a, 2 b, 2 c, 2 d, 2 e and 3 which are disposed adjacent to the radially outward side with respect to the transfer chamber 1 as shown in FIG. 6B. At this point of time, whilst the other of the transfer tables will be displaced towards the center of rotation, it can be seen that its amount of displacement will be small because of an angle that is made between the arm 7 a, 7 b and link 9 a, 9 b.

On the other hand, the latter handling robot A′ of identically directed operating type in the prior art is constructed as shown in FIG. 12 to FIG. 13B of the drawings attached hereto.

The handling robot A′ that is disposed within a transfer chamber has a cylindrical case 22 that is provided with a flange 24 at its upper end, and above the flange 24 there is provided a rotary table 23 such as to be rotatable and further displaceable vertically. And, a first driven shaft 25 is provided as projecting from the lower end surface of the rotary table 23 through the flange 24. And, the first driven shaft 25 is coupled to a first drive source 26 that is provided within the above mentioned case 22. Thus, the arrangement is so constructed that with the said drive source 26 operated to rotate the driven shaft 25, the said rotary table 23 may be rotated. Here, it should be noted that a drive source for vertically driving the rotary table is omitted from the illustration in the drawing.

The upper surface of the above mentioned rotary table 23 has the respective intermediate portions of a pair of first links 28 a and 28 b pivotally attached thereto. A pivotal section of one link 28 a of the pair of links 28 a and 28 b has fastened thereto one end of a second driven shaft 29 that is provided as extending within the case 22. The other end of the second driven shaft 29 has coupled thereto a second drive source 30 that is also provided within the above mentioned case 22. Thus, the arrangement is so constructed that the one link 28 a of the first pair of links 28 a and 28 b may be rotated via the second driven shaft 29 by the second drive source 30.

One end of each of the above mentioned pair of first links 28 a and 28 b has coupled thereto the corresponding one of a pair of second links 32 a and 32 b which are configured so as to be rotatable via a pair of second bearing shafts 31 a and 31 b, respectively. And, the forward ends of the pair of second links 32 a and 32 b have a first fork-like transfer table 8 a′ coupled thereto.

Also, the other end of each of the above mentioned first links 28 a and 28 b has coupled thereto a corresponding one of a pair of third links 35 a and 35 b which are configured so as to be rotatable via a pair of third bearing shafts 34 a and 34 b. And, the pair of third links 35 a and 35 b have at their forward ends a second fork-like transfer table 8 b′ coupled thereto.

And, whilst the above mentioned second bearing shaft 31 a is configured so as to be rotatable with respect to the first link 28 a and to be integral with the second link 32 a, the above mentioned second bearing shaft 31 b is configured so as to be integral with the first link 28 b and to be rotatable with respect to the second link 32 b. Also, whilst the third bearing shaft 34 a is configured so as to be rotatable with respect to the first link 28 a and to be integral with the said third link 35 a, the above mentioned third bearing shaft 34 b is configured so as to be integral with the first link 28 b and to be rotatable with respect to the third link 35 b.

The above mentioned two transfer tables 8 a′ and 8 b′ are deviated in position in a vertical direction and the first transfer table 8 a′ is displaced from the state shown in FIG. 12 in a retracting direction such that when the second transfer table 8 b′ is displaced in an advancing direction they may not interfere with each other. And, the two transfer tables 8 a′ and 8 b′ are then configured so as to be crossed in a state in which they are stacked one upon another vertically.

Each of the above mentioned bearing shafts 31 a and 31 b are projected at the lower sides of the first links 28 a and 28 b, respectively, and such projecting portions have fastened thereto a pair of second gears 36 a and 36 b which have an identical number of teeth. Also, each of the third bearing shafts 34 a and 34 b is projected towards each of the first links 28 a and 28 b, respectively and such projecting portions have fastened thereto, as shown in FIG. 13, a pair of third gears 37 a and 37 b which have an identical number of teeth, respectively. It should be noted that these pairs of gears, 36 a and 36 b; and 37 a and 37 b, respectively constitute synchronous mechanisms 38 a and 38 b.

The above mentioned two synchronous mechanisms 38 a and 38 b will enable one link 28 a of the pair of first links 28 a and 28 b to be rotated in the direction of normal rotation or reverse rotation by the drive source 30 via the second driven shaft 29. The rotation will then be transmitted via the first and second synchronous mechanisms 38 a and 38 b to the other link 28 b of the first links 28 a and 28 b and the second links 32 a and 32 b as well as to the third links 35 a and 35 b to cause the pair of transfer tables 8 a′ and 8 b′ to operatively be projected and retracted in an identical direction as shown in FIGS. 13A and 13B of the drawings attached hereto.

It may be noted at this point that the above mentioned conventional two handling robots A and A′ have each been expected to provide a functional effect as a two arm robot by virtue of the advantage that a pair of transfer tables are provided and can alternately or consecutively be used for each of a variety of stations. It has been found, however, that as a matter of reality there arises following problems.

More specifically, since a process order has been determined, it should be noted that where a wafer that has been processed in a process chamber station is successively transferred to a series of the succeeding stations, each of these stations contains a wafer that is being or that has been processed. Then, if a wafer that has been processed within a given station is exchanged with an unprocessed wafer therein, what the above mentioned former handling robot A in the prior art does is first to support an unprocessed wafer W₁ on one of the transfer tables 8 a and then to turn the handling robot A so as to oppose the other vacant transfer table 8 b to the station 2 e where the wafers are to be exchanged with each other (see FIG. 7).

Then, it will project the vacant transfer table 8 b into the station 2 e and receive a processed wafer W₂ thereon (FIG. 8) to convey it into the transfer chamber 1. Thereafter, the handling robot A will be turned by 180° (FIG. 9) to oppose the transfer table 8 a supporting the unprocessed wafer W₁ to the above mentioned station 2 e and will then operatively project it into the station 2 e (FIG. 10) and to convey the said unprocessed wafer W₁ into the station 2 e. The transfer table 8 a that has then become vacant will be operatively retracted into the transfer chamber 1 (FIG. 11).

In this way, with the former handling robot A in the prior art, the problem has been encountered that each time a wafer is exchanged for a given station, it has to be turned by 180° thus prolonging the cycle time for each individual wafer exchanging operation.

On the other hand, if the latter handling robot A′ in the prior art is adopted, it can be seen that since the two transfer tables 8 a′ and 8 b′ are configured so as to be operatively projected and retracted in an identical direction, not only can a given workpiece be conveyed into a given process chamber but another workpiece can be conveyed out thereof while the handling robot A′ remains deactuated. Whilst with the handling robot A′ there is thus the advantage that the cycle time for conveying a workpiece into and out of a process chamber can be reduced and the projecting/retracting operation for each of the two transfer tables 8 a′ and 8 b′ can be carried out with a single drive source or a small number of drive sources, not the feature that is lacking with the former handling robot A in the prior art, it has been found, however, that there have arisen there the problems which are mentioned below.

Specifically, inasmuch as the said handling robot A′ allows the state in which the two transfer tables are stacked one upon another vertically at an identical position to be projected and retracted each time the transfer operation is performed, there has always been a fear that a dust that had deposited upon the upper transfer table might fall onto the upper surface of a workpiece that was held on the lower transfer table, thus contaminating a surface of the lower workpiece.

Also, the two transfer tables being deviated in position vertically, the lacking of a vertical displacement feature will, if those transfer tables are alternately projected and retracted without moving vertically, cause the width of a vertical aperture of the gate to be enlarged by the amount of vertical deviation of the transfer tables with an unfavorable result with respect to an air tight retention of such a gate portion. For this reason, the above mentioned handling robot A′ of an identically directed operating type in the prior art has involved the problem that it requires a vertical displacement mechanism to be provided, thus complicating its structure for this provisioning. Also, when a workpiece is delivered onto a workpiece supporting table in a process chamber, it has been necessary that at least one transfer table should be moved vertically a distance by which it has been deviated in a vertical direction. Thus, an additional process step has been required and this has been an undesirable obstruction for the cycle time of a workpiece input and output conveyance to be reduced.

Accordingly, the present invention has been made with the foregoing problems taken into account, and has for its generic object to provide a handling robot that needs not to be turned at all or may be turned with a small angle in the order of 45° for a given process chamber, to enable a wafer that has been processed within a station and a wafer unprocessed within a transfer chamber to be exchanged with each other. It is also a further object of the present invention to provide a handling robot whereby a dust dispersed from one transfer table may not fall onto both transfer tables and yet a vertical displacement mechanism is not required, without moving the entire robot vertically the width of a gate in a vertical direction can only be for a single transfer table, a minimum number of simplified mechanisms can only be included, the air tight feature of a gate portion gives a performance substantially equal to the said former type in the prior art and at the same time the cycle time for a workpiece input and output conveyance can be substantially reduced.

SUMMARY OF THE INVENTION

In order to achieve the object mentioned above, there is provided in accordance with the present invention, in a certain aspect thereof, a handling robot, which comprises a first and a second robotic link mechanism which are so configured as to be jointly rotatable, each robotic link mechanism having a transfer table at a forward end thereof to mount a workpiece and adapted to operatively be projected and retracted in a radial direction of the transfer table when they operatively extended and contracted, and in which the first and second robotic link mechanisms are arranged so that the two transfer tables may be located in a narrow angular range.

At this point it should be noted that when one of the robotic link mechanisms is operatively projected, the other robotic link mechanism will be operatively retracted. The above mentioned projecting operation will cause the transfer table to be projected from the transfer chamber into the process chamber station to deliver a workpiece mounted on the transfer table into the process chamber, or alternatively to receive a workpiece from the process chamber station. Also, the retracting operation will cause the transfer table to be retracted from the process chamber into the transfer chamber side. Also, the two robotic link mechanisms may be in a retracting state so as to be rotated in the transfer chamber.

According to the above mentioned construction, it is possible to alternate a projecting operation and a retracting operation for the first and second transfer tables within a narrow angular range, this causing a wafer that has been processed in a station and an unprocessed wafer in the transfer chamber to be exchanged with each other without turning the handling robot at all or by only slightly turning the same for a given station. This will allow the cycle time for exchanging the wafers with each other to be largely reduced.

In the construction mentioned above, each of the first and second robotic mechanisms comprises:

a plurality of bosses which may be rotated independently from each other;

a drive source respectively connected to each of the bosses;

two pairs of arms which are composed of one or two arms respectively provided for each of the bosses;

a pair of links coupled to each pair of such arms at forward ends thereof, respectively; and

the transfer tables coupled to the pair of links at forward ends thereof, respectively.

And also, in the construction mentioned above, it is preferred that there should be provided;

a first, a second and a third boss as aforesaid;

a first arm as aforesaid that is provided for the first boss on;

a second and a third arm as aforesaid which are provided for the second boss;

a fourth arm as aforesaid that is provided for third boss on a side surface thereof;

a first transfer table as aforesaid that is provided for the first and second arms at a forward end thereof via a pair of links; and

a second transfer table as aforesaid that is provided for the third and fourth arms at a forward end thereof via a pair of links.

In the construction mentioned above,

the first arm is radially directed and is provided for the first boss on a side surface thereof;

the second and third arms are radially directed and provided for the second boss on a side surface thereof so that they may be located at diametrically opposite sides of the second boss, respectively;

the fourth arm is radially directed and is provided for the third boss on a side surface thereof.

According to the preceding construction, it can be seen that with the first and second arms being rotated together in a direction in which they approach a side of the first transfer table that is coupled thereto via the links, the said first transfer table will be operatively projected. On the other hand, the third and fourth arms will then be rotated together in a direction in which they depart from the second transfer table that is coupled thereto via the links, this allowing the said second transfer table to be held in a retracted state.

In the above mentioned state, it can also be seen that with the third and fourth arms at this time being rotated together in a direction in which they approach the second transfer table that is coupled thereto via the links, the second transfer table will be operatively projected whilst the first transfer table on the contrary will be operatively retracted.

Also, in the above mentioned construction, it is preferred that there should be provided:

a first and a second boss as aforesaid;

a first and a second arms as aforesaid which are provided for the first boss;

a third and a fourth arms as aforesaid which are provided for the second boss;

a first transfer table as aforesaid that is provided for the first and fourth arms at a forward end thereof via the pair of links; and

a second transfer table as aforesaid that is provided for the second and third arms at a forward end thereof via the pair of links.

In the construction mentioned above,

the first and second arms are radially directed and are provided for the first boss on a side surface thereof so that they may be located at diametrically opposite sides of the first boss, respectively;

the third and fourth arms are radially directed and are provided for the second boss so that they may be located at diametrically opposite sides of the second boss, respectively, one of the third and fourth arms being provided on a surface of the second boss and the other of the third and fourth arms being located on a top surface of the second boss via an upstanding leg column.

And also, in the construction mentioned above,

the first and second arms are radially directed and are provided for the first boss on a surface thereof so that they may be located at diametrically opposite sides of the first boss, respectively;

the third and fourth arms are radially directed and provided for the second boss on a side surface thereof so that they may be located at diametrically opposite sides of the second boss, respectively.

According to the preceding construction, it can be seen that with the first and fourth arms being rotated together in a direction in which they approach a side of the the first transfer table that is coupled thereto via the the links, the said first transfer table will be operatively projected. On the other hand, the second and third arms will be rotated in a direction in which they depart from the second transfer table that is coupled thereto via the links, this allowing the second transfer table to be held in a retracted state.

In the above mentioned state, it can also be seen that with the second and third arms at this time being rotated together in a direction in which they approach the second transfer table via the said links, the second transfer table will be operatively projected whilst the first transfer table on the contrary will be operatively retracted.

Also, in the construction mentioned above, the first and second robotic link mechanisms can be arranged so that the two transfer tables may be stacked one above another vertically.

Also, the first and second robotic link mechanisms can be arranged so that the two transfer tables may not be stacked one above another vertically but may be deviated in position in a rotary direction thereof.

According to the preceding construction, it can be seen that since the transfer tables are not stacked one above another, even if a dust is dispersed from either of the transfer tables, there will be no contamination thereby of a wafer on the other transfer table. It should be noted at this point that whilst if a wafer is put into and out of a given station, the two robotic link mechanisms need to be rotated by an angle corresponding to an amount of deviation, the deviation, being in an order in which the two transfer tables are not stacked one upon another, will be slight.

Also, the construction mentioned above may be constituted of:

a rotary table;

a first drive source operatively connected to the rotary table;

a first and a second drive link mechanism supported by the rotary table so as to be each rotatable;

a second drive source operatively connected to one of the first and second drive link mechanisms;

a first and a second driven link mechanism, each having one end coupled to each of the first and second drive link mechanisms at a forward end thereof, respectively, so that they may be synchronously rotated following a rotation of each of the drive link mechanisms; and

a first and a second transfer table as aforesaid connected to the first and second driven link mechanisms, respectively.

According to the preceding construction, the first and second robotic link mechanisms will have their respective drive link mechanisms aforesaid rotate with a drive shaft so that the two transfer tables may be alternately projected and retracted via the driven link mechanisms. And, by causing the said rotary table to rotate with another drive source, the said two robotic mechanisms will be jointly rotated.

It should also be noted that any of said drive link mechanisms and the driven link mechanisms of the first and second robotic link mechanisms may be constituted by either a parallel link mechanism or a belt mechanism.

Also, in the construction mentioned above, it is preferable that the first and second robotic link mechanisms should be arranged so that the two transfer tables coupled respectively thereto may have an identical position in a vertical direction.

According to the preceding construction, it is advantageous that the projecting and retracting operation for the transfer tables by the first and second robotic link mechanisms is carried out at an identical position in a vertical direction. For this reason, not only is a vertical displacement mechanism required there but also this construction will enable the vertical width of a gate of the transfer chamber through which they are projected and retracted to be only for a single transfer table as aforesaid to enhance the air tightness of such a gate portion whilst simplifying the entire construction of the handling robot.

BRIEF EXPLANATION OF THE DRAWINGS

The present invention will better be understood from the following detailed description and the drawings attached hereto showing certain illustrative embodiments of the present invention. In this connection, it should be noted that such embodiments as illustrated in the accompanying drawings are not intended to limit the present invention, but rather to facilitate an explanation and understanding thereof.

In the accompanying drawings:

FIG. 1 is a diagrammatic top plan view of a semiconductor manufacturing equipment as an example of such equipment of multiple chamber type;

FIG. 2 is an exploded perspective view showing the relationship between a transfer chamber and a conventional handling robot;

FIG. 3 is a perspective view showing a conventional handling robot;

FIGS. 4A and 4B are explanatory views, each showing a transfer table attitude regulating mechanism;

FIG. 5 is a cross sectional view showing a conventional arm rotating mechanism;

FIGS. 6A and 6B are operational explanatory views for a conventional handling robot;

FIG. 7 is an operational explanatory view for a given station of a conventional handling robot;

FIG. 8 is an operational explanatory view for a given station of a conventional handling robot;

FIG. 9 is an operational explanatory view for a given station of a conventional handling robot;

FIG. 10 is an operational explanatory view for a given station of a conventional handling robot;

FIG. 11 is an operational explanatory view for a given station of a conventional handling robot;

FIG. 12 is a perspective view of another conventional handling robot;

FIGS. 13A and 13B are operational explanatory views of the other conventional handling robot;

FIG. 14 is a cross sectional view showing a boss section of a first embodiment of the handling robot according to the present invention;

FIG. 15 is a front view showing the first embodiment of the present invention;

FIG. 16 is a top plan view showing the first embodiment of the present invention;

FIG. 17 is a perspective view showing the first embodiment of the present invention;

FIG. 18 is a perspective view showing the first embodiment of the present invention;

FIG. 19 is a cross sectional view showing a boss section in a second embodiment of the present invention;

FIG. 20 is a front view showing the second embodiment of the present invention;

FIG. 21 is a top plan view showing the second embodiment of the present invention;

FIG. 22 is a perspective view showing the second embodiment of the present invention;

FIG. 23 is a perspective view showing the second embodiment of the present invention;

FIG. 24 is a cross sectional view showing a boss section in a third embodiment of the present invention;

FIG. 25 is a front view showing the third embodiment of the present invention;

FIG. 26 is a top plan view showing the third embodiment of the present invention;

FIG. 27 is a perspective view showing the third embodiment of the present invention;

FIG. 28 is an operational explanatory view of each of the above mentioned embodiments for a given station;

FIG. 29 is an operational explanatory view of each of the above mentioned embodiments for a given station;

FIG. 30 is an operational explanatory view for a given station in each of the embodiments of the present invention;

FIG. 31 is an operational explanatory view for a given station in each of the embodiments of the present invention;

FIG. 32 is a cross sectional view showing a boss section in a fourth embodiment of the present invention;

FIG. 33 is a front view showing the fourth embodiment of the present invention;

FIG. 34 is a top plan view showing the fourth embodiment of the present invention;

FIG. 35 is a perspective view showing the fourth embodiment of the present invention;

FIG. 36 is a cross sectional view showing a boss section in a fifth embodiment of the present invention;

FIG. 37 is a front view showing the fifth embodiment of the present invention;

FIG. 38 is a top plan view showing the fifth embodiment of the present invention;

FIG. 39 is a perspective view showing the fifth embodiment of the present invention;

FIG. 40 is a cross sectional view showing a boss section in a sixth embodiment of the present invention;

FIG. 41 is a front view showing the sixth embodiment of the present invention;

FIG. 42 is a top plan view showing the sixth embodiment of the present invention;

FIG. 43 is a perspective view showing the sixth embodiment of the present invention;

FIG. 44 is an operational explanatory view for a given station in the fourth embodiment of the present invention;

FIG. 45 is an operational explanatory view for a given station in the fourth embodiment of the present invention;

FIG. 46 is an operational explanatory view for a given station in the fourth embodiment of the present invention;

FIG. 47 is an operational explanatory view for a given station in the fourth embodiment of the present invention;

FIG. 48 is an operational explanatory view for a given station in the fourth embodiment of the present invention;

FIG. 49 is a top plan view showing an operating state of a seventh embodiment of the present invention;

FIG. 50 is a top plan view showing a stand-by state in the seventh embodiment of the present invention;

FIG. 51 is a cross sectional view showing the construction of the seventh embodiment of the present invention;

FIG. 52 is a cross sectional view showing the construction of an eighth embodiment of the present invention;

FIG. 53 is a perspective view showing a first bidirectional rotary link mechanism;

FIG. 54 is an operational explanatory view showing the first bidirectional rotary link mechanism;

FIG. 55 is an explanatory view showing a relationship between the link length of the first bidirectional rotary link mechanism and the rotary angle or the like;

FIG. 56 is a graph showing the changing rotary angles of the first and second drive shafts with respect to the rotary angle of a motor link of the first bidirectional rotary link mechanism;

FIG. 57 is a perspective view showing a second bidirectional rotary link mechanism;

FIG. 58 is an operational explanatory view of the second bidirectional rotary link mechanism;

FIG. 59 is an explanatory view showing a relationship between the link length of the second bidirectional rotary link mechanism and the rotary angle or the like;

FIG. 60 is a graph showing the changing rotary angles of the first and second drive shafts with respect to the rotary angle of a motor link of the first bidirectional rotary link mechanism;

FIG. 61 is a top plan view showing a stand-by state in a modified example of the eighth embodiment of the present invention;

FIG. 62 is an explanatory view showing a relationship between the link length of a third bidirectional rotary link mechanism and the rotary angle or the like;

FIG. 63 is a graph showing the changing rotary angles of the first and second drive shafts with respect to the rotary angle of a motor link of the third bidirectional rotary link mechanism;

FIG. 64 is an explanatory view showing a relationship between the link length of a fourth bidirectional rotary link mechanism and the rotary angle or the like;

FIG. 65 is a graph showing the changing rotary angles of the first and second drive shafts with respect to the rotary angle of a motor link of the fourth bidirectional rotary link mechanism;

FIG. 66 is a perspective view showing a fifth bidirectional rotary link mechanism;

FIG. 67 is an explanatory view showing a stand-by state of the fifth bidirectional rotary link mechanism;

FIG. 68 is an explanatory view showing an operating state of the fifth bidirectional rotary link mechanism;

FIG. 69 is a cross sectional view showing another example of the fifth bidirectional rotary link mechanism;

FIG. 70 is an explanatory view showing a stand-by state of the other example of the fifth bidirectional rotary link mechanism;

FIG. 71 is an explanatory view showing an operating state of the fifth bidirectional rotary link mechanism; and

FIG. 72 is a cross sectional view showing the ninth embodiment of the present invention.

BEST MODES FOR CARRYING OUT THE INVENTION

Hereinafter, suitable embodiments of the present invention with respect to a handling robot will be set forth with reference to the accompanying drawings hereof.

A detailed explanation will now be given to a certain embodiments of the present invention, i.e. with regard to the first embodiment thereof shown in FIGS. 14 to 18, the second embodiment thereof shown in FIGS. 19 to 23, the third embodiment thereof shown in FIGS. 24 to 27, the fourth embodiment thereof shown in FIGS. 32 to 35, the fifth embodiment thereof shown in FIGS. 36 to 39, the sixth embodiment thereof shown in FIGS. 40 to 43, the seventh embodiment thereof shown in FIGS. 49 to 51, and further the eighth embodiment thereof shown in FIGS. 52 to 71, and still further the ninth embodiment thereof shown in FIG. 72. In such explanation, it should be noted that the same components designated with the same reference numerals represent the same components used in up to FIG. 13 for the constructions in the prior art, and a repeated explanation thereof will be omitted.

(A First Embodiment)

A transfer chamber 1 has a central region in which the first, second and third, ring shaped bosses 120 a, 120 b and 120 c are supported coaxially with one another via bearings (not shown) so as to be each individually rotatable in a state in which they are stacked one upon another successively from a lower side thereof.

And, inside of the above mentioned ring shaped bosses 120 a, 120 b and 120 c, correspondingly three disk shaped bosses 121 a, 121 b and 121 c are supported via bearings (not shown) coaxially with one another by a frame la side of the said transfer chamber 1 so as to be each individually rotatable.

A set of the said ring shaped bosses 120 a, 120 b and 120 c and a set of the said disk shaped bosses 121 a, 121 b and 121 c which respectively correspond thereto are magnetically connected together by three magnetic couplings 122 a, 122 b and 122 c, in a rotary direction thereof. In this construction, it should be noted that in order to maintain the interior of the said transfer chamber 1 in an evacuated state, a sealing partition wall 17 is provided between the said ring shaped bosses 120 a, 120 b and 120 c and the said disk shaped bosses 121 a, 121 b and 121 c.

The above mentioned disk shaped bosses 121 a, 121 b and 121 c are connected to rotary shafts 123 a, 123 b and 123 c, respectively, which are disposed coaxially with one another in an axial center portion thereof. Of these rotary shafts, the first and second rotary shafts 123 a and 123 b are hollow, the second rotary shaft 123 b is fittedly inserted into the first rotary shaft 123 a, and the third rotary shaft 123 c is fittedly inserted into the second rotary shaft 123 b.

And, the said first and third rotary shafts 123 a and 123 c are coupled to the output shaft 125 a of a first motor unit 124 a via a coupling mechanism such as a timing belt. Also, the said second rotary shaft 123 b is coupled to the output shaft 125 b of a second motor unit 124 b via a coupling mechanism such as a timing belt.

The above mentioned motor units 124 a and 124 b can each be a combination of a servo motor and a reduction gear such that the rotary speeds of their respective output shafts 125 a and 125 b may each be reduced with an extremely large speed reduction ratio and may each be accurately controlled with respect to a normal rotation as well as a reverse rotation thereof. Also, a pair of coupling mechanisms are provided for respectively coupling the said output shafts 125 a and 125 b together and the said rotary shafts 123 a, 123 b and 123 c together and have an identical ratio of coupling rotation.

There are provided a first arm 126 a for the said first ring shaped boss 120 a, a second and a third arm 126 b and 126 b for the said second ring shaped boss 120 b and further a fourth arm 126 d for the said third ring shaped boss 120 c so that these arms may each be radially projected, and their respective forward ends are each provided with a rotary joint.

The circumferential arrangement relationship of the said arms 126 a, 126 b, 126 c and 126 d and their respective lengths to the said joints provided at the said forward ends are set forth below. More specifically, the said second and third arms 126 b and 126 c are projected diametrically (180°) with respect to the said second ring shaped boss 120 b.

And, it should be noted that the radii of the rotary joints of the said first and second arms 126 a and 126 b (which are each the length from the center of the boss section to the joint) are represented by R_(1 and R) ₁′ and the radii of the rotary joints of the said third and fourth arms 126 c and 126 d are represented by R₂ and R₂′. In this embodiment, note also that R₁>R₂, R₁′>R₂′, R₁=R₁′ and R₂=R₂′. And, the respective rotary joints of the said first and second arms 126 a and 126 b which are longer are configured to take an identical position in the axial direction of the center of rotation of the ring shaped boss whereas the respective joints of the said third and fourth arms 126 c and 126 d which are shorter are configured to take an identical position in the axial direction of the center of rotation of the ring shaped boss and that is a position which is inside of that of the said first and second arms and is lower than that.

Each of the respective rotary joints of the said first and second arms 126 a and 126 b which are longer has coupled thereto one end of each of a first and a second link 127 a and 127 b, respectively, having an identical length, so as to be rotatable. The respective other ends of the said two links 127 a and 127 b have coupled thereto a said first transfer table 8 a via a transfer table attitude regulating mechanism. In this regard it should be noted that the length of the said two links 127 a and 127 b is configured, as shown in FIG. 16, to be a length such that the point of coupling with the said first transfer table 8 a in a state in which it is coupled therewith may, in a state in which the said two arms 126 a and 126 b are made linear diametrically with respect of the center of rotation of the said boss section, be deviated from the line which connects them towards the operative projecting direction of the said transfer table. It is these which constitutes a first robotic link mechanism D₁.

Also, each of the respective joints of the said third and fourth arms 126 c and 126 d which are shorter has coupled thereto one end of each of the said third and fourth links 127 c and 127 d, respectively, having an identical length, so as to be rotatable. The respective other ends of the said two links 127 c and 127 d have coupled thereto a said second transfer table 8 b via a transfer attitude regulating mechanism. In this regards it should be noted that the length of the said two links 127 c and 127 d is configured as shown in FIG. 16 to be a length such that the point of coupling with the said second transfer table 8 b in a state in which it is coupled therewith may, in a state in which the said two arms 126 c and 126 d are made linear diametrically with respect to the center of rotation of the said boss section, be deviated from the line which connects them towards the operatively projecting direction of the said transfer table and may take a substantially identical position below the above mentioned first transfer table 8 a. It is these which constitutes a second robotic link mechanism D₂.

In this first embodiment of the present invention, with the said first motor unit 124 a being rotationally driven, the said first and third ring shaped bosses 120 a and 120 c will be jointly rotated via the said first and third rotary shafts 123 a and 123 c, the said first and third disk shaped bosses 121 a and 121 c and the said magnetic couplings 122 a and 122 c. Also, with the said second motor unit 124 b being rotated, the said second ring shaped boss 120 b will likewise be rotated.

As shown in FIG. 16, a stand-by attitude is assumed to be in a state in which the said first and second arms 126 a and 126 b are made linear diametrically of the said boss section, and the said third and fourth arms 126 c and 126 d assume an identical position above the said first and second arms 126 a and 126 b.

In this state, if the said first and second arms 126 a and 126 b are rotated jointly so that they may approach the said first transfer table 8 a by rotating each of the said ring shaped bosses 120 a, 120 b and 120 c, respectively, the said first transfer table 8 a will then be operatively projected as shown in FIG. 17. On the other hand, the said third and fourth arms 126 c and 126 d will then be rotated jointly so that they may depart from the said second transfer table 8 b, this causing the said second transfer table 8 b to be operatively retracted slightly in the direction opposite to the direction in which the said first transfer table 8 a is operatively projected.

On the contrary, if the said third and fourth arms 126 c and 126 d are rotated jointly so that they may approach the said second transfer table 8 b, the said second transfer table 8 b will be operatively projected as shown in FIG. 18. On the other hand, the said first and second arms 126 a and 126 b will be rotated jointly so that they may depart from the said first transfer table 8 a, this causing the said first transfer table 8 a to be operatively retracted slightly in the direction opposite to the direction in which the said second transfer table 8 b will be operatively projected.

Also, in a stand-by state as shown in FIG. 16, by rotating the said ring shaped bosses 120 a, 120 b and 120 c in an identical direction, the said two transfer tables 8 a and 8 b will be turned within the said transfer chamber 1.

(A Second Embodiment)

The said transfer chamber 1 has a central region in which a first and a second ring shaped bosses 130 a and 130 b are supported coaxially with one another via bearings (not shown) so as to be each individually rotatable in a state in which they are stacked one upon another successively from a lower side thereof.

And, inside of the above mentioned ring shaped bosses 130 a and 130 b, correspondingly two disk shaped bosses 131 a and 131 b are supported via bearings (not shown) coaxially with one another by a frame la side of the said transfer chamber 1 so as to be each individually rotatable.

A set of the said ring shaped bosses 130 a and 130 b and a set of the said disk shaped bosses 131 a and 131 b which respectively correspond thereto are magnetically connected together by two magnetic couplings 132 a and 132 b, in a rotary direction thereof. In this construction, it should be noted that in order to maintain the interior of the said transfer chamber 1 in an evacuated state, a sealing partition wall 17 is provided between the said ring shaped bosses 130 a and 130 b and the said disk shaped bosses 131 a and 131 b.

The above mentioned disk shaped bosses 131 a and 131 b are connected to rotary shafts 133 a and 133 b, respectively, which are disposed coaxially with each other in an axial center portion thereof. Of these rotary shafts, the first rotary shaft 133 a is hollow, and the second rotary shaft 133 b is fittedly inserted into the first rotary shaft 133 a.

And, the said first rotary shafts 133 a is coupled to the output shaft 135 a of a first motor unit 134 a via a coupling mechanism such as a timing belt. Also, the said second rotary shaft 133 b is coupled to the output shaft 135 b of a second motor unit 134 b via a coupling mechanism such as a timing belt.

The above mentioned motor units 134 a and 134 b can each be a combination of a servo motor and a reduction gear such that the rotary speeds of their respective output shafts 135 a and 135 b may each be reduced with an extremely large speed reduction ratio and may each be accurately controlled with respect to a normal rotation as well as a reverse rotation thereof. Also, a pair of coupling mechanisms are provided for respectively coupling the said output shafts 135 a and 135 b together and the said rotary shafts 133 a and 133 b together and have an identical ratio of coupling rotation.

The above mentioned first ring shaped boss 130 a has on side surfaces thereof a first and a second arm 136 a and 136 b which are protrudingly mounted thereat towards diametrically opposite sides thereof. Also, the said second ring shaped boss 130 a is provided on a side surface thereof with a third arm 136 c and the said ring shaped boss 130 a is provided at an axial center portion on a top surface thereof with a fourth arm 136 d via a leg column 136 e, the said arms 136 c and 136 d being protrudingly mounted thereat towards diametrically opposite sides thereof.

The circumferential arrangement relationship of the said arms 136 a, 136 b, 136 c and 136 d and their respective lengths to the rotary Joints that is provided at the said forward ends are set forth below.

More specifically, the lengths R₁ and R₂ from the centers of the respective boss sections to the respective rotary joints of the said first and second arms 136 a and 136 b which are protrudingly mounted at the said first ring shaped boss 130 a are made different with R₁>R₂.

Also, the lengths R₂′ and R₁′ from the respective boss section centers of the said third and fourth arms 136 c and 136 d which are protrudingly mounted at the said second ring shaped boss 130 b to their rotary joints are here adapted to satisfy the relationship: R₁′>R₂′. Also, in this embodiments, note that the relationships: R₁=R₁′ and R₂=R₂′. And, the rotary joint of the said first arm 136 a that is longer is provided on a forward end upper surface of the said first arm 136 a, the rotary joint of the said fourth arm 136 d is provided on a forward end lower surface of the said fourth arm 136 d, and the said two rotary joints assume an identical position in an axial direction of the center of rotation of a said ring shaped boss.

The respective rotary joints of the said second arms 136 b and the said third arms 136 c which are shorter are provided on their respective arm forward end upper surfaces and assume an identical position in their axial directions.

Each of the respective rotary joints of the said first and fourth arms 136 a and 136 d which are longer has one end of each of a first and a fourth link 137 a and 137 d, respectively, having an identical length, so as to be rotatable. The respective other ends of the said two links 137 a and 137 d have coupled thereto a said first transfer table 8 a via a transfer table attitude regulating mechanism. In this regard it should be noted that the length of these two links 137 a and 137 d is configured, as shown in FIG. 21, to be a length such that the point of coupling with the said first transfer table 8 a in a state in which it is coupled therewith may, in a state in which the said two arms 136 a and 136 d are made linear diametrically with respect to the center of rotation of the said boss section, be deviated from the line which connects them towards the operatively projecting direction of the said first transfer table 8 a. It is these which constitutes a first robotic link mechanism D₁′.

Also, each of the respective joints of the said second and third arms 136 b and 136 c which are shorter has coupled thereto one end of each of a second and a third link 137 b and 137 c, respectively, having an identical length, so as to be rotatable. The respective other ends of the said two links 137 b and 137 c have coupled thereto a said second transfer table 8 b via a transfer attitude regulating mechanism. In this regards it should be noted that the length of the said two links 137 b and 137 c is configured, as shown in FIG. 21, to be a length such that the point of coupling with the said second transfer table 8 b in a state in which it is coupled therewith may, in a state in which the said two arms 136 b and 136 c are made linear diametrically with respect to the center of rotation of the said boss section, be deviated from the line which connects them towards the operatively projecting direction of the said transfer table and may take a substantially identical position below the above mentioned first transfer table 8 a. It is these which constitutes a second robotic link mechanism D₂′.

In this second embodiment of the present invention, with the said first motor unit 134 a being rotationally driven, the said first ring shaped boss 130 a will be jointly rotated via the said first rotary shaft 133 a, the said first disk shaped boss 131 a and the said magnetic coupling 132 a. Also, with the said second motor unit 134 b being rotated, the said second ring shaped boss 130 b will likewise be rotated.

As shown in FIG. 21, a stand-by attitude is assumed to be in a state in which the said first and fourth arms 136 a and 136 d are made linear diametrically of the said boss section, and the said second and third arms 136 b and 136 c are made linear diametrically of the said boss section at the same position as the said first and fourth arms 136 a and 136 d in the turning direction.

In this state, if the said first and fourth arms 136 a and 136 d are rotated jointly so that they may approach the said first transfer table 8 a by rotating each of the said ring shaped bosses 130 a and 130 c, respectively, the said first transfer table 8 a will then be operatively projected as shown in FIG. 22. On the other hand, the said second and third arms 136 b and 136 c will then be rotated jointly so that they may depart from the said second transfer table 8 b, this causing the said second transfer table 8 b to be operatively retracted slightly in the direction opposite to the direction in which the said first transfer table 8 a is operatively projected. The retracting operation should then be within a range in which the said second transfer table 8 b may not contact the said leg column 136 e.

On the contrary, if the said second and third arms 136 b and 136 c are rotated jointly so that they may approach the said second transfer table 8 b, the said second transfer table 8 b will be operatively projected as shown in FIG. 23. On the other hand, the said first and fourth arms 136 a and 136 d will be rotated jointly so that they may depart from the said first transfer table 8 a, this causing the said first transfer table 8 a to be operatively retracted slightly in the direction opposite to the direction in which the said second transfer table 8 b will be operatively projected. The retracting operation should then be within a range in which the said transfer table 8 b may not contact the said leg column 136 e.

Also, in the stand-by state, by rotating the said ring shaped bosses 130 a and 130 b in an identical direction, the said two transfer tables 8 a and 8 b will be operatively turned within the said transfer chamber 1.

(A Third Embodiment)

The said transfer chamber 1 has a central region in which a first and a second ring shaped bosses 140 a and 140 b are supported coaxially with one another via bearings (not shown) so as to be each individually rotatable in a state in which they are stacked one upon another successively from a lower side thereof.

And, inside of the above mentioned ring shaped bosses 140 a and 140 b, correspondingly two disk shaped bosses 141 a and 141 b are supported via bearings (not shown) coaxially with one another by a frame 1 a side of the said transfer chamber 1 so as to be each individually rotatable.

A set of the said ring shaped bosses 140 a and 140 b and a set of the said disk shaped bosses 141 a and 141 b which respectively correspond thereto are magnetically connected together by two magnetic couplings 142 a and 142 b, in a rotary direction thereof. In this construction, it should be noted that in order to maintain the interior of the said transfer chamber 1 in an evacuated state, a sealing partition wall 17 is provided between the said ring shaped bosses 140 a and 140 b and the said disk shaped bosses 141 a and 141 b.

The above mentioned disk shaped bosses 141 a and 141 b are connected to rotary shafts 143 a and 143 b, respectively, which are disposed coaxially with one another in an axial center portion thereof. Of these rotary shafts, the first rotary shaft 143 a is hollow, and the second rotary shaft 143 b is fittedly inserted into the first rotary shaft 143 a.

And, the said first rotary shafts 143 a is coupled to the output shaft 145 a of a first motor unit 144 a via a coupling mechanism such as a timing belt. Also, the said second rotary shaft 143 b is coupled to the output shaft 145 b of a second motor unit 144 b via a coupling mechanism such as a timing belt.

The above mentioned motor units 144 a and 144 b can each be a combination of a servo motor and a reduction gear such that the rotary speeds of their respective output shafts 145 a and 145 b may each be reduced with an extremely large speed reduction ratio and may each be accurately controlled with respect to a normal rotation as well as a reverse rotation thereof. Also, a pair of coupling mechanisms are provided for respectively coupling the said output shafts 145 a and 145 b together and the said rotary shafts 143 a and 143 b together and have an identical ratio of coupling rotation.

The above mentioned first ring shaped boss 140 a has on side surfaces thereof a first and a second arm 146 a and 146 b which are protrudingly mounted thereat towards diametrically opposite sides thereof. Also, the said second ring shaped boss 140 b is provided on a side surface thereof with a third arm 146 c and fourth arm 146 d which are protrudingly mounted thereat towards diametrically opposite sides thereof.

The circumferential arrangement relationship of the said arms 146 a, 146 b, 146 c and 146 d and their respective lengths to the rotary joints that is provided at the said forward ends are set forth below.

More specifically, the lengths R₁ and R₂ from the centers of the respective boss sections to the respective rotary joints of the said first and second arms 146 a and 146 b which are protrudingly mounted at the said first ring shaped boss 140 a are made different with R₁>R₂ as shown in FIG. 25.

Also, the lengths R₂′ and R₁′ from the respective boss section centers to the respective rotary joints of the said third and fourth arms 146 c and 146 d which are protrudingly mounted at the said second ring shaped boss 140 b are here adapted to satisfy the relationship: R₁′>R₂′ as shown in FIG. 25. Also, in this embodiments, note that the relationships: R₁=R₁′ and R₂=R₂′. The said fourth arm 146 d that is longer is protrudingly mounted to orient in a diametrically opposite direction to the said arm 146 a and the said boss section whereas the said third arm 146 c that is shorter is protrudingly mounted to orient in a diametrically opposite direction to the said second arm 146 b and the said boss section.

And, the rotary joint of the said first arm 146 a that is longer is provided to take an identical position on the respective forward end upper surfaces of the said first and fourth arms 146 a and 146 d in an axial direction. Also, the said second and third arms 146 b and 146 c which are shorter, the said second arm 146 b has its rotary joint that is provided on a forward end upper surface thereof and the said third arm 146 c has its rotary joint that is provided on a forward end lower surface thereof so that they may assume an identical position in their respective axial directions. It is these which constitutes a first robotic link mechanism D₁.

The above mentioned first and fourth arms 146 a and 146 d which are longer are, as noted above, protrudingly mounted at diametrically opposite sides of the said boss section, and each of the respective rotary joints of the said arms 146 a and 146 d has coupled thereof one end of the each of said first and fourth links 147 a and 147 d, respectively, having an identical length, so as to be rotatable. The respective other ends of the said links 147 a and 147 d has coupled thereto a said first transfer table 8 a via a transfer attitude regulating mechanism. In this regard it should be noted that the length of the said two links 147 a and 147 d is configured to be a length such that the point of coupling with the said first transfer table 8 a in a state in which it is coupled therewith may, in a state in which the said two arms 146 a and 146 d are made linear diametrically with respect to the center of rotation of the said boss section, be deviated from the line which connects them to the operatively projecting direction of the said first transfer table 8 a.

Also, each of the respective joints of the said second and third arms 146 b and 146 c which are shorter has coupled thereto each of one end of a second and a third link 147 b and 147 c, respectively, having an identical length, so as to be rotatable. The respective other ends of the said two links 147 b and 147 c have coupled thereto a second transfer table 8 b via a transfer attitude regulating mechanism. In this regards it should be noted that the length of the said two links 147 b and 147 c is configured, to be a length such that the point of coupling with the said transfer table 8 b in a state in which it is coupled therewith may, in a state in which the said two arms 146 b and 146 c are made linear diametrically with respect to the center of rotation of the said boss section, be deviated from the line which connects them towards the operatively projecting direction of the said transfer table and may take a substantially identical position below the above mentioned first transfer table 8 a. It is these which constitutes a second robotic link mechanism D₂″.

In this third embodiment of the present invention, it can be seen, as shown in FIG. 26, that if the said first and second motor units 144 a and 146 b are rotated simultaneously and in their respective directions which are opposite to each other from the stand-by state in which the said arms are linearly arranged diametrically of the said boss station over an identical angle so that, for example, the said first and fourth arms 146 a and 146 d may be jointly rotated to reach the side of the said first transfer table 8 a coupled therewith, the said first transfer table 8 a will be operatively projected via the said links 147 a and 147 d. Then, the said second and third arms 146 a and 146 c will be operated so that they may depart from the said second transfer table 8 b, and as a result the said second transfer table 8 b will be retracted towards the axial center side of the said boss section.

It can also be noted that by rotating the said drive sources 144 a and 144 b reversely, the said second transfer table 8 b will be operatively projected whereas the said first transfer table 8 b will be operatively retracted.

In each of the embodiments mentioned above, the said motor units are driven controlledly with respect to their angle of rotation so that each of the said transfer tables 8 a and 8 b may be displaced from the inside of the said transfer chamber 1 to a predetermined position in a given process chamber, i. e. a workpiece attracting position and vice versa.

And, according to each of the embodiments mentioned above, it can be seen that where a wafer that has been processed in a given station is transferred successively to the other stations, as shown in FIGS. 28 to 31, the method will involve a series of steps to be carried out. Thus, firstly, an unprocessed wafer W₁ will be mounted on the one transfer table 8 a and thereafter it will be opposed to a station 2 e where it is to be exchanged with another wafer, by turning the handling robot A (FIG. 28).

Subsequently, the vacant transfer table 8 b will be operatively projected into the said station 2 e to receive a processed wafer W₂ (FIG. 29) and then to convey it into the said transfer chamber 1. Thereafter, the said first transfer table 8 a having the said unprocessed wafer W₁ mounted thereon will be operatively projected into the said station 2 e (FIG. 30) to deliver the said unprocessed wafer W₁ into the said station 2 e whilst operatively retracting the transfer table 8 a that becomes vacant into the said transfer chamber 1 so as to be ready for a next process step (FIG. 31).

In this manner, the handling robot in each of the embodiments of the present invention enables a processed wafer and an unprocessed wafer to be exchanged for a given station without turning the handling robot.

(A Fourth Embodiment)

Referring to FIGS. 32 to 35, a said transfer chamber 1 has a central region in which three ring shaped bosses 240 a, 240 b and 240 c are supported coaxially with one another via bearings (not shown) so as to be each individually rotatable in a state in which they are stacked one upon another successively from a lower side thereof.

And, inside of the above mentioned ring shaped bosses 240 a, 240 b and 240 c, correspondingly three disk shaped bosses 241 a, 241 b and 241 c are supported via bearings (not shown) coaxially with one another by a said frame la side of the said transfer chamber 1 so as to be each individually rotatable.

A set of the said ring shaped bosses 240 a, 240 b and 240 c and a set of the said disk shaped bosses 241 a, 241 b and 241 c which respectively correspond thereto are magnetically connected together by three magnetic couplings 242 a, 242 b and 242 c, in a rotary direction thereof. And, in order to maintain the interior of the said transfer chamber 1 in an evacuated state, a sealing partition wall 17 is provided between the said ring shaped bosses 240 a, 240 b and 240 c and the said disk shaped bosses 241 a, 241 b and 241 c.

The above mentioned disk shaped bosses 241 a, 241 b and 241 c are connected to rotary shafts 243 a, 243 b and 243 c, respectively, which are disposed coaxially with one another in an axial center portion thereof. Of these rotary shafts, the first and second rotary shafts 243 a and 243 b are hollow, the second rotary shaft 243 b is fittedly inserted into the first rotary shaft 243 a, and the third rotary shaft 243 c is fittedly inserted into the second rotary shaft 243 b.

And, the said first and third rotary shafts 243 a and 243 c are coupled to the output shaft 245 a of a first motor unit 244 a via a coupling mechanism such as a timing belt. Also, the said second rotary shaft 243 b is coupled to the output shaft 245 b of a second motor unit 244 b via a coupling mechanism such as a timing belt.

The above mentioned motor units 244 a and 244 b can each be a combination of a servo motor and a reduction gear such that the rotary speeds of their respective output shafts 245 a and 245 b may each be reduced with an extremely large speed reduction ratio and may each be accurately controlled with respect to a normal rotation as well as a reverse rotation thereof. Also, a pair of coupling mechanisms are provided for respectively coupling the said output shafts 245 a and 245 b together and the said rotary shafts 243 a, 243 b and 243 c together and have an identical ratio of coupling rotation.

There are provided a first arm 246 a for the said first ring shaped boss 240 a, a second and a third arm 246 b and 246 b for the said second ring shaped boss 240 b and further a fourth arm 246 d for the said third ring shaped boss 240 c so that these arms may each be radially projected, and their respective forward ends are each provided with a rotary joint.

The respective rotary joint radii of the above mentioned arms 246 a, 246 b, 246 c and 246 d (i. e. the length from the boss section center to the rotary joint which is hereinafter identically referred to) R are made an identical size. And, the respective rotary joints of the said first and second arms 246 a and 246 b are configured to take an identical position in the axial direction of the center of rotation of a said ring shaped boss whereas the respective joints of the said third and fourth arms 246 c and 246 d are configured to take an identical position in the axial direction of the center of rotation of a said ring shaped boss, which is lower than that for the said first and second arms 246 a and 246 b.

Each of the respective rotary joints of the said arms 246 a, 246 b, 246 c and 246 d has coupled thereto one end of each of a first, a second, a third and a fourth link 247 a, 247 b, 247 c and 247 d, respectively, which have an identical length but is longer than the length R of the said arms, so as to be rotatable. And, there is coupled a said first transfer table 8 a to the forward end lower surfaces of the above mentioned first and second links 247 a and 247 b via a transfer table attitude regulating mechanism and a first robotic link mechanism B1 is thereby constituted. Also, there is coupled a said second transfer table 8 b to the forward end upper surfaces of the said third and fourth links 247 c and 247 d via a transfer table attitude regulating mechanism and a second robotic link mechanism B₂ is thereby constituted.

Then, the said transfer table 8 a of the first robotic link mechanism B₁ is configured to be in a state in which, for example, the said first and second arms 246 a and 246 b are made linear diametrically of the said boss section and the said transfer table 8 a is operatively retracted into a ring shaped boss side and hence in a so called stand-by state. Also, the said transfer table 8 b of the second robotic link mechanism B₂ is likewise configured to be in a stand-by state when the said third and fourth arms 246 c and 246 d are made diametrically linear. And, the respective transfer tables 8 a and 8 b of the said first and second robotic link mechanisms B₁ and B₂ each in a stand-by state are positionally deviated in the rotary direction of a said ring shaped boss (FIG. 34), and this state constitutes a stand-by state of the handling robot. And, each of the said transfer tables 8 a and 8 b may be operatively projected and retracted radially of a said ring shaped boss by a rotation thereof, from the said stand-by state of the handling robot. Also, it is in this stand-by state that the handling robot can be rotated. And, if one of the said transfer tables is then operatively projected, the other transfer table can be operatively retracted further interiorly from the said stand-by state.

The amount of the said positional deviation in a rotary direction of each of the respective transfer tables 8 a and 8 b of the above mentioned two robotic link mechanisms B₁ and B₂ is such that at least the said two transfer tables 8 a and 8 b may not interfere in a rotary direction and should preferably be an amount of deviation within a range in which two wafers do not interfere with each other when the wafers are mounted on the said transfer tables 8 a and 8 b, respectively.

Since the respective transfer tables 8 a and 8 b of the said two robotic link mechanisms B₁ and B₂ do not then interfere in a rotary direction, they assume an identical position in an axial direction of the center of rotation (i. e. in a vertical direction) of a said ring shaped boss as shown in FIG. 33. In this connection it should be noted that the respective forward end portions of the said first and second arms 246 a and 246 b are each curved outwards so that the respective forward end portions of the said third and fourth arms 246 c and 246 d may not interfere with each other.

In this fourth embodiment of the present invention, by individually rotating the said ring shaped bosses 240 a, 240 b and 240 c, it can be seen that one of the said first and second transfer tables 8 a and 8 b will be operatively projected and the other will be operatively retracted, from a stand-by state as shown in FIG. 35. Then, the respective forward end portions of the said third and fourth arms 246 c and 246 d are allowed to pass through the inside of the said first and second arms 246 a and 246 b and hence there should be no interference with one another.

By rotating the said ring shaped bosses 240 a, 240 b and 240 c in an identical rotary direction in a stand-by state as shown in FIG. 34, it can be seen that the handling robot will be rotated within the said transfer chamber 1.

FIGS. 44 to 48 show a series of operational steps in this fourth embodiment of the present invention. First, the entire handling robot in the stand-by state will be rotated so that in a state in which the transfer table 8 a of one robotic link mechanism B1 has an unprocessed wafer W₁ mounted thereon, the one having a wafer mounted thereon, i. e. the vacant transfer table 8 b of the other robotic link mechanism B2 may be opposed to a process chamber station 2 e in which a processed wafer W₂ is present (FIG. 44).

Then, the said vacant transfer table 8 b of the said other robotic link mechanism B2 will be projected into the above mentioned process chamber station 2 e whereupon with the said processed wafer W₂ mounted thereon it will be conveyed out (FIG. 45). Thereafter, the entire handling robot will be rotated until the said transfer table 8 a of the robotic link mechanism B1 having the said unprocessed wafer W₁ mounted thereon is opposed to the said process chamber station 2 e where it is to be processed (FIG. 46). The angle of rotation in this state can sufficiently be for an amount of deviation of the said two transfer tables 8 a and 8 b in their rotary directions and may be, for example, not more than 90°.

In this state, the said transfer table 8 a of the robotic link mechanism Bl having the said unprocessed wafer W₁ mounted thereon will be projected into the said process chamber station 2 e to set this wafer W₁ within this process chamber station 2 e (FIG. 47). Then, the said vacant transfer table 8 a will be retracted towards the side of the said transfer chamber 1 (FIG. 48).

Thereafter, the entire handling robot will be rotated until the said vacant transfer table 8 a is opposed to a process chamber station 2 a where a next processing operation is to be carried out. By repeating similar process steps to the above, a next processing operation for the said processed wafer W₂ on the other transfer table 8 b will be carried out in the process chamber station 2. It may be noted, however, that for opposing the other transfer table 8 b to the said process chamber station 2 e, it is necessary to rotate the handling robot oppositely to the above.

In this manner, the handling robot according to the present embodiment of the invention enables a processed wafer and an unprocessed wafer to be exchanged for a given station only by turning the handling robot over a small angle, for example, not more than 90°.

Furthermore, since the said two transfer tables 8 a and 8 b do not overlap one upon another, it can be seen that if a dust falls from one transfer table side, this will never contaminate the upper surface of the other transfer table. Also, since the said two transfer tables 8 a and 8 b assume an identical position in an axial direction of the center of rotation (i. e. in a vertical direction) of a said ring shaped boss, it will be noted that each of the said transfer tables can be projected and retracted for a given gate without moving the handling robot vertically. Also a vertical dimension of the gate 6 for each of the process chamber stations into which these transfer tables 8 a, 8 b may be thrusted into is such a size that only one of the transfer tables can be thrusted into, thus the vertical dimension can be minimized. And those in this embodiment is the same as in the below mentioned embodiment.

[A Fifth Embodiment)

FIGS. 36 to 39 show a fifth embodiment of the present invention. There are protrudingly mounted radially a first and a second arm 256 a and 256 b to side surfaces of a first ring shaped boss 250 a, a third arm 256 c to a side surface of a second ring shaped boss 250 b and a fourth arm 256 d to an axial center portion on the top surface of the said second ring shaped boss 250 b via an upstanding leg column 256 e, respectively, and a rotary joint is provided on the forward end upper surface of each of the said arms.

The respective rotary joints radii R of the above mentioned arms 256 a, 256 b, 256 c and 256 d are an identical size. And, the respective rotary joints of the above mentioned first and fourth arms 256 a and 256 d assume an identical position in a vertical direction whereas the respective rotary joints of the said second and third arms 256 b and 256 c assume an identical position in a vertical direction and are lower than those of the said first and fourth arms 256 a and 256 d.

Each of the respective rotary joints of the above mentioned arms 256 a, 256 b, 256 c and 256 d has one end of each of a first, a second, a third and a fourth link 257 a, 257 b, 257 c and 257 d which have an identical length but are longer than the length R of each of the above mentioned arms, so as to be rotatable. And, there is coupled a said first transfer table 8 a to the respective forward end lower surfaces of the said first and fourth links 257 a and 257 d via a transfer table attitude regulating mechanism and a first robotic link mechanism B₁′ is thereby constructed. Also, there is coupled a said second transfer table 8 b to the respective forward end upper surfaces of the said second and third links 257 b and 257 c via a transfer table attitude regulating mechanism and a second robotic link mechanism B₂′ is constructed thereby.

In this case, the said transfer table 8 a of the first robotic link mechanism B₁′ is configured to be in a state in which it is retracted towards the ring shaped boss side and thus in a so called stand-by state, for example when the said first and fourth arms 256 a and 256 d are made linear diametrically. Also, the said transfer table 8 b of the second robotic B₂′ is likewise configured to be in a stand-by state when the said second and third arms 256 b and 256 c are made linear diametrically. And, the said two transfer tables 8 a and 8 b in such a stand-by state are then positionally deviated in a rotary direction of a said ring shaped boss by a rotation thereof, and it is this state which constitutes a stand-by state of the handling robot (FIG. 38). And, from this state each of the said transfer tables 8 a and 8 b is, likewise the above mentioned fourth embodiment, projected and retracted in a radial direction of a ring shaped boss, and also in this state the handling robot is designed to be rotated. In this regard it should also be noted that the amount of deviation of the said two transfer tables 8 a and 8 b each in their respective rotary directions is likewise the case of the above mentioned fourth embodiment.

Since the said two transfer tables 8 a and 8 b do not then overlap in a rotary direction, they assume an identical position in a vertical direction as shown FIG. 37. Also, the forward end portion of the said first arm 256 a is curved outwards so that the forward end portion of the said third arm 256 c may not interfere therewith. And, the process steps in this fifth embodiment are substantially the same as those in the above mentioned fourth embodiment.

(A Sixth Embodiment)

FIGS. 40 to 43 show a sixth embodiment of the present invention. There are protrudingly mounted radially a first and a second arm 266 a and 266 b to side surfaces of a first ring shaped boss 260 a, and a third and a fourth arm 266 c and 266 d to side surfaces of a second ring shaped boss 260 b, respectively, and their respective rotary joints are provided on the respective forward end lower surfaces of the said first and third arms 266 a and 266 c and the respective forward end upper surfaces of the said second and fourth arms 266 b and 266 d.

The respective rotary joints radii R of the above mentioned arms 266 a, 266 b, 266 c and 266 d are an identical size. And, there are provided the respective rotary joints of the said first and third arms 266 a and 266 c on their lower surfaces and the respective rotary joints of the said second and fourth arms 266 b and 266 d on their upper surfaces. And, the respective rotary joints of the said first and fourth arms 266 a and 266 d assume an identical position in a vertical direction whereas the respective rotary joints of the said second and third arms 266 b and 266 c assume an identical position in a vertical direction and are lower than those of the said first and fourth arms 266 a and 266 d.

Each of the respective rotary joints of the above mentioned arms 266 a, 266 b, 266 c and 266 d has one end of each of a first, a second, a third and a fourth link 267 a, 267 b, 267 c and 267 d which have an identical length but are longer than the length R of each of the above mentioned arms, so as to be rotatable. And, there is coupled a said first transfer table 8 a to the respective forward end lower surfaces of the said first and fourth links 267 a and 267 d via a transfer table attitude regulating mechanism and a first robotic link mechanism B₁″ is thereby constructed. Also, there is coupled a said second transfer table 8 b to the respective forward end upper surfaces of the said second and third links 267 b and 267 c via a transfer table attitude regulating mechanism and a second robotic link mechanism B₂″ is constructed thereby.

In this case, the said transfer table 8 a of the first robotic link mechanism B₁″ is configured to be in a state in which it is most retracted towards the ring shaped boss side and thus in a so called stand-by state, when the said first and fourth arms 266 a and 266 d are made linear diametrically. Also, the said transfer table 8 b of the second robotic B₂″ is likewise configured to be in a stand-by state when the said second and third arms 266 b and 266 c are made linear diametrically. And, the said two transfer tables 8 a and 8 b in such a stand-by state are then positionally deviated in a rotary direction of a said ring shaped boss (FIG. 42), and it is this state which constitutes a stand-by state of the handling robot. And, from this state each of the said transfer tables 8 a and 8 b is, likewise the above mentioned fourth embodiment, projected and retracted in a radial direction of a ring shaped boss by a rotation thereof, and also in this state the handling robot is designed to be rotated. And, the amount of deviation of the said two transfer tables 8 a and 8 b in their respective rotary directions is substantially the same as the case of the above mentioned fourth embodiment.

Since the said two transfer tables 8 a and 8 b do not then overlap in a rotary direction, they assume an identical position in a vertical direction as shown FIG. 41. Also, the forward end portion of the said first arm 266 a is curved outwards so that the forward end portion of the said third arm 266 c may not interfere therewith. And, the process steps in this sixth embodiment is substantially the same as those in the above mentioned fourth embodiment.

(A Seventh Embodiment)

FIGS. 49 to 51 show a seventh embodiment of the present invention. In this seventh embodiment, too, like the above mentioned fourth to sixth embodiments, two transfer tables 8 a′ and 8 b′ are positionally deviated in a rotary direction of the robot and assume an identical position in a direction of the axis of a center of rotation.

FIGS. 49 and 50 diagrammatically show the construction and operation of the seventh embodiment and a specific construction thereof is illustrated in FIG. 51. As shown, it includes a rotary table 270 which is rotatably supported by a said frame la of a said transfer chamber 1 and a drive shaft 271 which is supported at the center of rotation of the said rotary table 270 rotatably with respect thereto. And, the above mentioned rotary table 270 is so arranged as to be driven normally and reversely by a first motor unit 272 a that is fastened to the frame la side of the said transfer table 1. Also, the said drive shaft 271 is so arranged as to be driven normally and reversely by a second motor unit 272 b that is fastened to the said rotary table 270 side.

A first and a second robotic link mechanism C₁ and C₂ which are disposed at both sides of the above mentioned drive shaft 271 include a pair of drive link mechanisms 273 and 274, respectively, which are constituted by a parallel link mechanism. The said first drive link mechanism 273 is constituted of a drive link 273 a and a driven link 273 b which are arranged in parallel to each other and a coupling link 273 c that is adapted to couple the respective forward ends of the said links 273 a and 273 b together. Also, the said second drive link mechanism 274 is constituted of a drive link 274 a and a driven link 274 b which are arranged in parallel to each other and a coupling link 274 c that is adapted to couple the respective forward ends of the said links 274 a and 274 b together.

And, the respective drive links 273 a and 274 a of the above mentioned drive link mechanisms 273 and 274 have their base section that is fastened and coupled to the above mentioned drive shaft 271. Also, the respective base ends of the said driven links 273 b and 274 b are journaled on the said rotary table 270 so that they may be spaced apart from each other with an angle α with respect to the center of rotation of the said rotary table 270.

The said coupling links 273 c and 274 c for their respective drive link mechanisms 273 and 274 have at their respective both ends a pair of supporting shafts 275 a and 275 b; and a pair of supporting shafts 276 a and 276 b, respectively, which are in turn provided for the said coupling links 273 c and 274 c with a pair of gears 277 a and 277 b which mesh with each other and a pair of gears 277 c and 277 d which mesh with each other, respectively, the said gears 277 a, 277 b, 277 c and 277 d having an identical number of teeth. Of these supporting shafts, the said shafts 275 a and 276 a located at the respective forward ends of the said drive links 273 a and 274 a are integrally coupled therewith, respectively, whereas the said supporting shafts 275 b and 276 b are adapted to be rotatable with respect to the said driven links 273 b and 274 b, respectively.

There are provided a first and a second driven link mechanism 278 and 279 which are coupled with the drive link mechanisms 273 and 274 at their forward end sides, respectively, of the said first and second robotic link mechanisms C₁ and C₂ and are each constituted by a parallel link configuration. The said first driven link mechanism 278 is comprised of a pair of drive link 278 a and driven link 278 b extending in parallel to each other and a coupling link 280 a that is coupled with the said links 278 a and 278 b. Also, the said second driven link mechanism 279 is comprised of a pair of drive link 279 a and driven link 279 b extending in parallel to each other and a coupling link 280 b that is coupled with the said links 279 a and 279 b.

Of the base ends of these links, the respective base ends of the said drive links 278 a and 279 a are integrally coupled with the said supporting shafts 275 b and 276 b at the respective sides of the said driven links 273 b and 274 b for the above mentioned first and second drive link mechanisms 273 and 274, respectively, whereas the respective base ends of the said driven links 278 b and 279 b are coupled with the said supporting shafts 275 a and 276 a, respectively, so as to be rotatable.

And, the said transfer tables 8 a′ and 8 b′ are integrally coupled with the said coupling links 280 a and 280 b at the respective forward end sides of the said driven link mechanisms 278 and 279, respectively. From the respective link configurations of the said driven link mechanisms 278 and 279 and the respective configurations of the said transfer tables 8 a′ and 8 b′, it can be seen that the said two transfer tables 8 a′ and 8 b′ assume an identical position vertically as shown in FIG. 52. Also, the base end sections of the said transfer tables 8 a′ and 8 b′ are configured so that they may not interfere with each other.

Furthermore, the said two transfer tables 8 a′ and 8 b′ in this case are disposed on the respective extensions of the said coupling links 280 a and 280 b at the respective forward end sides of the said two driven link mechanisms 278 and 279. Consequently, the said two transfer tables 8 a′ and 8 b′ are positionally deviated in a rotary direction by the above mentioned spaced-apart angle α with respect to the center of rotation of the said rotary table 270. At this point it should also be noted that there is shown a ferrofluidic seal 281 in FIG. 52.

An explanation will now be given with respect to the operation of this seventh embodiment of the invention.

If the said second motor unit 272 b is normally or reversely rotated in a stand-by state as shown in FIG. 50 to rotate the said drive shaft 271, for example, rightwards, the respective drive links 273 a and 274 a of the respective drive link mechanisms 273 and 274 of the said first and second robotic link mechanisms C₁ and C₂ will be jointly rotated rightwards.

Since this causes the said first and second driven link mechanisms 278 and 279 to be jointly rotated leftwards when operated by the said gears 277 a, 277 b, 277 c and 277 d as shown in FIG. 49, the transfer table 8 a′ of the said first robotic link mechanism C₁ will be operatively projected and the transfer table 8 b′ of the said second robotic mechanism C₂ will be operatively retracted. Then, the said transfer tables 8 a′ and 8 b′ will be operatively projected and retracted in the directions of angles α₁ and α₂, respectively, of the spaced-apart angle α of each of the said driven links 273 b and 274 b of the respective drive link mechanisms 273 and 274 of the respective drive link mechanisms 273 and 274.

If the said drive shaft 271 is rotated reversely, i. e. leftwards, the above mentioned operation will be reversed in a way that the transfer table 8 a′ of the said first robotic link mechanism C₁ will be operatively retracted along the direction of the said angle α₁ and the transfer table 8 b′ of the said second robotic link mechanism C₂ will be operatively projected along the direction of the said angle α₂.

With the said first motor unit 272 a being driven in the state of a stand-by attitude of FIG. 50, the said rotary table 270 will be rotated so that the said first and second robotic link mechanisms C₁ and C₂ may be jointly rotated.

(An Eighth Embodiment)

FIGS. 52 to 60 show an eighth embodiment of the present invention. This eighth embodiment makes use of the construction which is identical to that of the said seventh embodiment and in which the respective drive links 273 a and 274 a of the said drive link mechanisms 273 and 274 are made coaxial with each other and arranged so as to be driven by drive shafts which are separately attached to the said rotary table 270. It is characterized by a large link action on the operative projection side and a small link action on the operative retraction side.

As shown in FIGS. 52 to 60, the construction ahead of the respective drive link mechanisms 273 and 274 of the said first and second robotic link mechanisms C₁ and C₂ is made identical to the construction of the said seventh embodiment, and the said rotary table 270 is arranged so as to be rotated by the said first motor unit 272 a as in the said seventh embodiment.

The said rotary table 270 has its central region in which a first and second drive shaft 285 and 286 are supported coaxially with each other so as to be independently rotatable. And, the said first drive shaft 285 has fastened thereto at its forward end one end of the drive link 273 a of the link mechanism 273 of the said first robotic link mechanism C₁ whereas the said second drive shaft 286 has fastened thereto at its forward end one end of the drive link 274 a of the drive link mechanism 274 of the said second robotic link mechanism C₂.

The respective base ends of the said first and second drive shafts 285 and 286 are coupled via a first bidirectional rotary link mechanism X₁ to the said single second motor unit 272 b that is supported by the said rotary table 270, and are so configured that when the said second motor unit 272 b is rotated unidirectionally, the drive link mechanism 273 of the said first robotic link mechanism C₁ and the drive link mechanism 274 of the said second robotic link mechanism C₂ may be rotated in an identical direction and with different angles of rotation.

The said bidirectional rotary link mechanism X₁, as shown in FIGS. 53 to 55, comprises a first driven link 287 a having one end coupled to the said first drive shaft 285, a second driven link 287 b having one end coupled to the said second drive shaft 286, and a first and a second drive links 288 a and 288 b coupled to the respective forward ends of the said links 287 a and 287 b, respectively. The said two drive links 288 a and 288 b constitute a link construction in which their respective forwards ends are coupled together. And, the said respective forward ends of the said two links 288 a and 288 b have coupled to their coupling portion the forward end of a motor link 289 having one end fastened to the drive shaft of the said second motor unit 272 b that is supported by the above mentioned rotary table 270. The said motor link 289 is disposed inside of the above mentioned link mechanism.

FIGS. 54 and 55 diagrammatically show the above mentioned first bidirectional rotary link mechanism X_(1.) If the said second motor unit 272 b is driven to rotate the said motor link 289 with a predetermined angle θ rightwards as viewed from the above, the said bidirectional rotary link mechanism X₁ will be rotated as distorted rightwards as shown in FIGS. 54 and 55. Assuming that the angle of rotation of the said first driven link 287 a that is located at an upstream side in the rotary direction is θ₁ and that the angle of rotation of the said second driven link 287 b that is located at a down stream side is θ₂, it will follow that θ₁>θ₂. Also, the said motor link 289 is rotated reversely (i. e. leftwards), the relationship that θ₁<θ₂ will apply.

If the above mentioned operation is performed from a stand-by state of the said two transfer tables 8 a′ and 8 b′ as shown in FIG. 50, the angle θ₁ in the direction of a projection of the said first drive link mechanism 273 will be greater than the angle of rotation θ₂ in the direction of a retraction of the second drive link mechanism 274. As a result, the amount of movement in the direction of a retraction of the said second transfer table 8 b′ when the said first transfer table 8 a′ is operatively projected up to a predetermined position, will become relatively small as compared with the amount of a projecting movement of the above mentioned first transfer table 8 a′.

Now, with reference to FIGS. 55 and 56, an explanation will be given with respect to the fact that if the said bidirectional rotary link mechanism X₁ is constructed as shown in FIGS. 53 and 54, the angle of rotation θ₁ (θ₂) of a said link at an upstream side in the rotary direction of the said motor link 289 will be greater than the angle of rotation θ₂ (θ₁) at a downstream side. It is assumed here that the length of the said first and second driven links 287 a and 287 b is L₁, the length of the said first and second drive links 288 a and 288 b is L₂, the length of the said motor link 289 is L₃, the distance between the joint of coupling the said first and second drive links 288 a and 288 b together and the axial center O of the said first and second drive shafts 285 and 286 is R, the angle of rotation of the said motor link is θ, the angle of rotation of the said first driven link 287 a is θ₁, the angle of rotation of the said second driven link 287 b is θ₂ and the angle made by the said first and second driven links 287 a and 287 b is 2φ. Then, it will follow that θ₁ and θ₂ are expressed by the following equations (1) and (2) and indicated as shown in Table 1 below. They can also be graphed as shown in FIG. 56. In this connection it should be noted that the rightward rotations of the said motor link 289 are assumed to be in the minus in FIG. 56 and Table 1. $\begin{matrix} \begin{matrix} {{\theta_{1}(\theta)} = \quad {{\tan^{- 1}\quad \frac{L_{3}\sin \quad \theta}{{L_{3}\cos \quad \theta} - L_{4}}} - \left( {{\phi (0)} - {\phi (\theta)}} \right)}} \\ {= \quad {{\tan^{- 1}\quad \frac{L_{3}\sin \quad \theta}{{L_{3}\cos \quad \theta} - L_{4}}} - {\cos^{- 1}\quad \frac{L_{1}^{2} - L_{2}^{2} + \left( {L_{3} - L_{4}} \right)^{2}}{2{L_{1}\left( {L_{3} - L_{4}} \right)}}} +}} \\ {\quad {\cos^{- 1}\quad \frac{L_{1}^{2} - L_{2}^{2} + L_{3}^{2} + L_{4}^{2} - {2L_{3}L_{4}\cos \quad \theta}}{2L_{1}\sqrt{L_{3}^{2} + L_{4}^{2} - {2L_{3}L_{4}\cos \quad \theta}}}}} \end{matrix} & (1) \\ \begin{matrix} {{\theta_{2}(\theta)} = \quad {{\tan^{- 1}\quad \frac{L_{3}\sin \quad \theta}{{L_{3}\cos \quad \theta} - L_{4}}} + \left( {{\phi (0)} - {\phi (\theta)}} \right)}} \\ {= \quad {{\tan^{- 1}\quad \frac{L_{3}\sin \quad \theta}{{L_{3}\cos \quad \theta} - L_{4}}} + {\cos^{- 1}\quad \frac{L_{1}^{2} - L_{2}^{2} + \left( {L_{3} - L_{4}} \right)^{2}}{2{L_{1}\left( {L_{3} - L_{4}} \right)}}} -}} \\ {\quad {\cos^{- 1}\quad \frac{L_{1}^{2} - L_{2}^{2} + L_{3}^{2} + L_{4}^{2} - {2L_{3}L_{4}\cos \quad \theta}}{2L_{1}\sqrt{L_{3}^{2} + L_{4}^{2} - {2L_{3}L_{4}\cos \quad \theta}}}}} \end{matrix} & (2) \end{matrix}$

TABLE 1 θ θ 1 θ 2 −60 −107.684 −64.975 −30 −55.9221 −43.8053 0 0 0 30 43.80526 55.92212 60 64.97499 107.684 (unit in degree)

As will be apparent from the above equations (1) and (2), the graph in FIG. 56 and the able 1 above, the said first and second drive link mechanisms 273 and 274 that are rotated by the said first and second driven links 287 a and 287 b which are driven by a rotation of the said motor link 289 will each be rotated by θ₁ in a projecting operation and by θ₂ in a retracting operation, reducing the angle of action in a retracting operation compared with a projecting operation. It should be noted here that the diagram of FIG. 55 is presented applying where L₁:L₂:L₃:L₄=1:1:1.8:0.8.

FIGS. 57 to 60 show a second bidirectional rotary link mechanism X₂ as another example. This makes use a construction in which a motor link 289 that is rotated by the said second motor unit 272 b is coupled to an outside of a link mechanism that is identical in structure to the said first bidirectional rotary link mechanism X₁ shown in the above mentioned FIG. 53.

If this second bidirectional rotary link mechanism X₂ is adopted, it can be seen that when the said motor link 289 is rotated rightwards by a predetermined angle θ in FIGS. 57 and 58, the said bidirectional rotary link mechanism X₂ will, contrary to the above mentioned first case, be rotated as distorted leftwards. If it is then assumed that the angle of rotation of the said first driven link 287 a that is located at an upstream side in the direction of rotation of the said motor link 289 in this case is θ₁ and the angle of rotation of the said second driven link 287 b that is located at a downstream is θ₂, it will follow that θ₁>θ₂. In this connection it should be noted that the direction of rotation of each of the above mentioned angles θ₁ and θ₂ of the said second bidirectional rotary link mechanism X₂ is opposite to the direction for the said first bidirectional rotary link mechanism X₁. From this, it will be seen that the said drive shafts 285 and 286 of this second bidirectional rotary mechanism X₂ can be coupled with the first and second drive link mechanisms 273 and 274 shown in FIGS. 49 and 50 oppositely to the case where the said first bidirectional rotary link mechanism X₁ is adopted. Thus, the said drive shaft 285 that is fastened to the said driven link 287 a at an upstream side in the rotary direction towards rightwards of the said motor link 289 is coupled to the said second drive link mechanism 274 of the second robotic link mechanism C₂ whereas the said drive shaft 286 b that is fastened to the said driven link 287 b at a downstream side is coupled to the said first drive link mechanism 273 of the first robotic link mechanism C₁.

With respect to the said bidirectional rotary link mechanism X₂ of the construction shown in FIGS. 57 and 58, an explanation will be given with reference to FIGS. 59 and 60 of the fact that the angle of rotation θ₁ (θ₂) of a said link at an upstream side in the rotary direction is greater than the angle of rotation θ₂ (θ₁) of a said link at a downstream side.

Assuming here that the dimensions of the various constituent members of the said second bidirectional rotary link mechanism X₂ are the same as those of the said first bidirectional link mechanism X₁, it will follow that the angles θ₁ and θ₂ are expressed by the following equations (3) and (4) and indicated as shown by Table 2 below. It can also be graphed as shown in FIG. 60. In FIG. 60 and Table 2, it is assumed that the rightward rotation of the said motor link 289 is in the plus. $\begin{matrix} \begin{matrix} {{\theta_{1}(\theta)} = \quad {{{- \tan^{- 1}}\quad \frac{L_{3}\sin \quad \theta}{L_{4} - {L_{3}\cos \quad \theta}}} - \left( {{\phi (0)} - {\phi (\theta)}} \right)}} \\ {= \quad {{{- \tan^{- 1}}\quad \frac{L_{3}\sin \quad \theta}{L_{4} - {L_{3}\cos \quad \theta}}} - {\cos^{- 1}\quad \frac{L_{1}^{2} - L_{2}^{2} + \left( {L_{4} - L_{3}} \right)^{2}}{2{L_{1}\left( {L_{4} - L_{3}} \right)}}} +}} \\ {\quad {\cos^{- 1}\quad \frac{L_{1}^{2} - L_{2}^{2} + L_{3}^{2} + L_{4}^{2} - {2L_{3}L_{4}\cos \quad \theta}}{2L_{1}\sqrt{L_{3}^{2} + L_{4}^{2} - {2L_{3}L_{4}\cos \quad \theta}}}}} \end{matrix} & (3) \\ \begin{matrix} {{\theta_{2}(\theta)} = \quad {{{- \tan^{- 1}}\quad \frac{L_{3}\sin \quad \theta}{L_{4} - {L_{3}\cos \quad \theta}}} + \left( {{\phi (0)} - {\phi (\theta)}} \right)}} \\ {= \quad {{{- \tan^{- 1}}\quad \frac{L_{3}\sin \quad \theta}{L_{4} - {L_{3}\cos \quad \theta}}} + {\cos^{- 1}\quad \frac{L_{1}^{2} - L_{2}^{2} + \left( {L_{4} - L_{3}} \right)^{2}}{2{L_{1}\left( {L_{4} - L_{3}} \right)}}} -}} \\ {\quad {\cos^{- 1}\quad \frac{L_{1}^{2} - L_{2}^{2} + L_{3}^{2} + L_{4}^{2} - {2L_{3}L_{4}\cos \quad \theta}}{2L_{1}\sqrt{L_{3}^{2} + L_{4}^{2} - {2L_{3}L_{4}\cos \quad \theta}}}}} \end{matrix} & (4) \end{matrix}$

TABLE 2 θ θ 1 θ 2 −60 0.00 60.00 −30 15.50 32.09 0 0.00 0.00 30 −32.09 −15.50 60 −60.00 0.00 (unit in degree)

As will be apparent form the above equations (3) and (4), the graph in FIG. 60 and the Table 2 above, the said first and second drive link mechanisms 273 and 274 that are rotated by the said first and second driven links 287 a and 287 b which are driven by a rotation of the said motor link 289 will each be rotated by θ₁ in a projecting direction and by θ₂ in a retracting direction, reducing the angle of action in a retracting operation compared with a projecting operation. It should be noted here that the diagram of FIG. 59 is presented applying where L₁:L₂:L₃:L₄=1:1:1:2.

For the said second bidirectional rotary link mechanism X₂ of the above mentioned eighth embodiment of the invention, whilst the example has been shown in which the said drive shafts 285 and 286 of the respective drive link mechanisms 273 and 274 of the said first and second robotic link mechanisms C₁ and C₂ are coaxial, they may be spaced apart from each other by a distance S as shown in FIG. 61.

FIG. 62 shows a third bidirectional rotary link mechanism X₃ for driving a said pair of first and second robotic link mechanisms C₁′ and C₂′ when the said drive shafts 285 and 286 are spaced apart from each other. This construction is essentially the same as that of the said first bidirectional rotary link mechanism X₁ except that the drive shafts are spaced apart and an explanation of this example will follow that of the above mentioned first bidirectional rotary link mechanism X₁.

In FIG. 62, if the said motor link 289 is rotated rightwards by a predetermined angle θ, the said bidirectional rotary link mechanism X₃ will be rotated as distorted rightwards. If it is then assumed that the angle of rotation of the said first driven link 287 a that is located at an upstream side in the rotary direction is θ₁ and the angle of rotation of the said second driven link 287 b that is located at an downstream side is θ₂, the relationship that θ₁<θ₂ will apply. Also, the said motor link 289 is rotated reversely (i. e. leftwards), it will follow that θ₁>θ₂.

Referring to FIG. 62, an explanation will now be given of the fact that θ₁<θ₂ as mentioned above in this case.

The respective angles of rotation θ₁ and θ₂ of the said first and second driven links 287 a and 287 b when the said motor link 289 is rotated rightwards by the angle θ are expressed by the following equations (5) and (6) and, when L₁=L₂, are expressed by the equations (7) and (8) below. And, they can be graphed as shown in FIG. 63. In this connection it should be noted that the graph of FIG. 63 applies when L₁:L₂:L₃:L₄:S=1:1:1.8:0.8:0.2. And, they can be shown also by Table 3 below. $\begin{matrix} {\theta_{1} = {{\tan^{- 1}\quad \frac{{L_{3}\sin \quad \theta} - {D/2}}{{L_{3}\cos \quad \theta} - L_{4}}} + {\tan^{- 1}\quad \frac{D/2}{L_{3} - L_{4}}} - \left( {{\phi_{1}(0)} - {\phi_{1}(\theta)}} \right)}} & (5) \\ {\theta_{2} = {{\tan^{- 1}\quad \frac{{L_{3}\sin \quad \theta} + {D/2}}{{L_{3}\cos \quad \theta} - L_{4}}} - {\tan^{- 1}\quad \frac{D/2}{L_{3} - L_{4}}} + \left( {{\phi_{2}(0)} - {\phi_{2}(\theta)}} \right)}} & (6) \\ \begin{matrix} {\theta_{1} = \quad {{\tan^{- 1}\quad \frac{{L_{3}\sin \quad \theta} - {D/2}}{{L_{3}\cos \quad \theta} - L_{4}}} + {\tan^{- 1}\quad \frac{D/2}{L_{3} - L_{4}}} -}} \\ {\quad {{\cos^{- 1}\quad \frac{\sqrt{L_{3}^{2} + L_{4}^{2} + {D^{2}/4} - {2L_{3}L_{4}}}}{2L_{1}}} +}} \\ {\quad {\cos^{- 1}\quad \frac{\sqrt{L_{3}^{2} + L_{4}^{2} + {D^{2}/4} - {{DL}_{3}\sin \quad \theta} - {2L_{3}L_{4}\quad \cos \quad \theta}}}{2L_{1}}}} \end{matrix} & (7) \\ \begin{matrix} {\theta_{2} = \quad {{\tan^{- 1}\quad \frac{{L_{3}\sin \quad \theta} + {D/2}}{{L_{3}\cos \quad \theta} - L_{4}}} - {\tan^{- 1}\quad \frac{D/2}{L_{3} - L_{4}}} +}} \\ {\quad {{\cos^{- 1}\quad \frac{\sqrt{L_{3}^{2} + L_{4}^{2} + {D^{2}/4} - {2L_{3}L_{4}}}}{2L_{1}}} -}} \\ {\quad {\cos^{- 1}\quad \frac{\sqrt{L_{3}^{2} + L_{4}^{2} + {D^{2}/4} - {{DL}_{3}\sin \quad \theta} - {2L_{3}L_{4}\quad \cos \quad \theta}}}{2L_{1}}}} \end{matrix} & (8) \end{matrix}$

TABLE 3 θ θ 1 θ 2 −60 −106.71 −75.12 −30 −55.66 −49.09 0 0.17 −0.17 30 49.09 55.66 60 75.12 106.71 (unit in degree)

In this example as well, that of the said drive shafts which is largely rotated by a rotation of the said motor link 289 is coupled to that of the said drive link mechanisms 273 and 274 which is operatively projected.

It should be noted that the fourth bidirectional rotary link mechanism X₄ has a construction in which the said two drive shafts of the second bidirectional rotary link mechanism X₂ are spaced apart from each other.

In FIG. 64, if the said motor link 289 is rotated rightwards by a predetermined angle θ, the said bidirectional rotary link mechanism X₄ will be rotated as distorted leftwards as shown in FIG. 64. If it is then assumed that the angle of rotation of the said first driven link 287 a that is located at an upstream side in the rotary direction of the said motor link 289 b is θ₁ and the angle of rotation of the said second driven link 287 b that is located at a downstream side is θ₂, the relationship that θ₁>θ₂ will apply. Also, if the said motor link 289 is rotated reversely (i. e. leftwards), the relationship that θ₁<θ₂ will apply.

With reference to FIG. 64, an explanation will now be given of the fact that the relationship that θ₁<θ₂ applies in this case.

The respective angles of rotation θ₁ and θ₂ of the said first and second driven links 287 a and 287 b when the said motor link 289 is rotated by the angle θ, are expressed by the following equations (9) and (10) and, when L₁=L₂, are expressed by the equations (11) and (12). And, they can be graphed as shown in FIG. 65. In this connection it should be noted that the graph of FIG. 65 applies where L₁:L₂:L₃:L₄:D=1:1:1:2:0.2. And, if they are tabulated, Table 4 shows a result. $\begin{matrix} {\theta_{1} = {{{- \tan^{- 1}}\quad \frac{{L_{3}\sin \quad \theta} + {D/2}}{L_{4} - {L_{3}\cos \quad \theta}}} + {\tan^{- 1}\quad \frac{D/2}{L_{4} - L_{3}}} - \left( {{\phi_{1}(0)} - {\phi_{1}(\theta)}} \right)}} & (9) \\ {\theta_{2} = {{{- \tan^{- 1}}\quad \frac{{L_{3}\sin \quad \theta} - {D/2}}{L_{4} - {L_{3}\cos \quad \theta}}} - {\tan^{- 1}\quad \frac{D/2}{L_{4} - L_{3}}} - \left( {{\phi_{2}(0)} - {\phi_{2}(\theta)}} \right)}} & (10) \\ \begin{matrix} {\theta_{1} = \quad {{{- \tan^{- 1}}\quad \frac{{L_{3}\sin \quad \theta} + {D/2}}{L_{4} - {L_{3}\cos \quad \theta}}} + {\tan^{- 1}\quad \frac{D/2}{L_{4} - L_{3}}} -}} \\ {\quad {{\cos^{- 1}\quad \frac{\sqrt{L_{3}^{2} + L_{4}^{2} + {D^{2}/4} - {2L_{3}L_{4}}}}{2L_{1}}} +}} \\ {\quad {\cos^{- 1}\quad \frac{\sqrt{L_{3}^{2} + L_{4}^{2} + {D^{2}/4} + {{DL}_{3}\sin \quad \theta} - {2L_{3}L_{4}\quad \cos \quad \theta}}}{2L_{1}}}} \end{matrix} & (11) \\ \begin{matrix} {\theta_{2} = \quad {{{- \tan^{- 1}}\quad \frac{{L_{3}\sin \quad \theta} - {D/2}}{L_{4} - {L_{3}\cos \quad \theta}}} - {\tan^{- 1}\quad \frac{D/2}{L_{4} - L_{3}}} +}} \\ {\quad {{\cos^{- 1}\quad \frac{\sqrt{L_{3}^{2} + L_{4}^{2} + {D^{2}/4} - {2L_{3}L_{4}}}}{2L_{1}}} +}} \\ {\quad {\cos^{- 1}\quad \frac{\sqrt{L_{3}^{2} + L_{4}^{2} + {D^{2}/4} - {{DL}_{3}\sin \quad \theta} - {2L_{3}L_{4}\quad \cos \quad \theta}}}{2L_{1}}}} \end{matrix} & (12) \end{matrix}$

TABLE 4 θ θ 1 θ 2 −60 5.72 59.86 −30 18.50 31.76 0 0.17 −0.17 30 −13.76 −18.50 60 −59.86 −5.72 (unit in degree)

In the case of this example, the said first drive shaft that is coupled with the said first driven link 287 a is coupled to the drive section of the said first robotic link mechanism C₁′ shown in FIG. 52 whereas the said second drive shaft that is coupled with the said second driven link 287 b is coupled to the drive section of the said second robotic link mechanism C₂′.

Whilst each of the above mentioned first, second, third and fourth bidirectional rotary link mechanism X₁, X₂, X₃ and X₄ has been explained in connection with an example in which it makes use of a link mechanism, it should be noted that it may make use of a elliptical gear mechanism in another example.

FIG. 66 shows a fifth bidirectional rotary link mechanism X₅ which constitutes the latter example.

A first elliptical gear 291 and a first circular gear 292 are fastened to an output shaft 290 of a said second motor unit 272 b. A second elliptical gear 293 which meshes with the above mentioned first elliptical gear 291 and a second circular gear 294 which meshes with the above mentioned first circular gear 292 are both fastened to the one drive shaft 285 and another drive shaft 286 of the said drive shafts which are disposed coaxially in the said first and second robotic link mechanisms, respectively. The said elliptical gears 291 and 293 are fastened to the said shafts 285 and 290, respectively.

In this construction, if the said rotary shaft 290 of the second motor unit 272 b is rotated, for example, from a neutral state as shown in FIG. 67 leftwards by an angle θ1 as shown in FIG. 68, the said second elliptical gear 293 will be rotated rightwards by an angle θ₂. Then, the oppositely disposed attitudes of the said two elliptical gears 291 and 293 will meet the relationship that θ₁<θ₂. On the other hand, the angle of rotation of the said second circular gear 294 is θ₁. This will cause the said first drive shaft 285 and the said second drive shaft 286 to be rotated rightwards by θ₂ and θ₁, respectively. With the relationship that θ₁<θ₂, the said first drive shaft 285 will be rotated more than the said second drive shaft 286.

On the other hand, if the said rotary shaft 290 is rotated from the said neutral state as shown in FIG. 67 rightwards by the angle θ₁, likewise the above the said second elliptical gear 293 will be rotated leftwards by the angle θ₂ and the said second circular gear 294 will be rotated leftwards by the angle θ₁. Then, the oppositely disposed attitudes of the said two elliptical gears 291 and 293 will meet the relationship that θ₁>θ₂. Consequently, now in order for the angle of rotation of the said second drive shaft 286 to be θ₂ leftwards and for the angle of rotation of the said first drive shaft 285 to be θ₁ (θ₂>θ₁), the said rotary shaft 290 will be rotated rightwards by the angle θ₂ that is greater than that of the above. This will cause the said second elliptical gear 293 to be rotated leftwards by the angle θ₁ whilst causing the said second circular gear 294 to be rotated leftwards by the angle θ₂. From this, it can be seen that by rotating the said second motor unit 272 b rightwards by the angle θ₂, the said first and second drive shafts 285 and 286 will be rotated leftwards by the angles θ₁ and θ₂, respectively and that with the relationship that θ₁<θ₂, the said second drive shaft 286 will be rotated more than the said first drive shaft 285.

Accordingly, in case the above mentioned first and second drive shafts 285 and 286 have coupled, respectively, the said first robotic link mechanism C₁ and the said second robotic mechanism C₂ shown in FIG. 49 thereto, it can be seen that when the said first robotic link mechanism C₁ is operatively projected and the said second robotic link mechanism C₂ is operatively retracted, the said second motor unit 272 b will be rotated leftwards by the angle θ₁ and that they are conversely operated, it will be rotated rightwards by the angle θ₂.

Whilst the above mentioned fifth bidirectional rotary link mechanism X₅ is constructed by a combination of elliptical gears and circular gears, it should be noted that the said circular gears 292 and 294 may be replaced by a pair of elliptical gears 292′ and 294′ which mesh with each other as shown in FIGS. 69 and 70.

FIG. 71 shows an operational state in that case. Here it should be noted that the angle of rotation of the said first drive shaft 285 when the said motor unit 272 b is rotated from its neutral state by a certain angle will be made equal to the angle of rotation of the said second drive shaft 286 when the said motor unit 272 b is rotated reversely by the same angle and that an identical computing method may be employed for controlling the said first and second robotic link mechanisms C₁ and C₂ only with different symbols and they are made more readily controllable thereby.

(A Ninth Embodiment)

Whilst the said drive link mechanisms and the said driven link mechanisms of the said first and second robotic link mechanisms C₁ and C₂; C₁′ and C₂′ in the above mentioned seventh and eighth embodiments are each comprised of a parallel link mechanism, such a pair of parallel link mechanisms may be alternatively replaced by a belt link construction.

FIG. 72 shows one robotic link mechanism D, which comprises: a first arm 301 that is rotatably supported by a rotary table (not shown); a second arm 302 that is rotatably coupled to the forward end of the said first arm 301; a transfer table 303 that is rotatably coupled to a forward end portion of the said second arm 302; a first pulley 304 that is supported at a rotary base portion of the above mentioned first arm 301 coaxially therewith; a second pulley 306 that is supported in the said first arm 301 by being coupled to a portion for coupling the said first and second arms 301 and 302 together, coaxially with the centers of rotation thereof and at a shaft 305; a third pulley 307 that is supported in the said second arm 302; a fourth pulley 309 that is supported so as to be fastened to a rotary shaft 308 of the above mentioned transfer table 303 at a forward end portion of the said second arm 302; a first belt 310 that is wound on the above mentioned first and second pulleys 304 and 306; and a second belt 311 that is wound on the said third and fourth pulley 307 and 309.

And, the said rotary base portion of the first arm 301 is coupled to a first motor unit 315 via a driven pulley 312, a drive pulley 313 and a belt 314 whereas the said first pulley 304 has a shaft 316 that is coupled to a second motor unit 317. The ratio in diameter of the above mentioned first and second pulleys 304 and 306 is set to be 2:1, and the ratio in diameter of the said third and fourth pulleys 307 and 309 is set to be 1:2.

In the construction mentioned above, if in a state in which the said second motor unit 317 is halted, the said first motor unit 315 is driven to rotate the said first arm 301 in a direction, the said first pulley 304 will be brought into a state in which it is reversely rotated with a same angle of rotation relative to the said first arm 301. The angle of rotation of the said first pulley 304 will be transmitted to the second pulley 306 via the first belt 310 as double increased in speed so that the said second arm 302 may be rotated in a direction opposite to a rotary direction of the first arm 301 with a rotary angle two times greater than a rotary angle thereof. Then, the said third pulley 307 that is located at the rotary base side of the said second arm 302 will, like the above mentioned first pulley 304, be relatively rotated in the direction opposite to the rotary direction of the said second arm 302, this causing the said transfer table 303 to be rotated in a direction opposite to the rotary direction of the said second arm 302 and with a ½ angle of rotation.

A rotary operation of normal or reverse rotation by the above mentioned first motor unit 315 of the said transfer table 303 will cause it to be operatively projected and retracted radially thereof relative to the said rotary base portion of the first arm 301. And, by rotating the said first and second motor units 315 and 317 in an identical direction with an identical angle of rotation, the entire robotic link mechanism D aforesaid will be rotated.

With regard to the present embodiment, whilst an explanation has been given to one of the robotic link mechanism only, actually a pair of such robotic link mechanisms are used as in the previously mentioned embodiments and they are cooperated so that when one of the said transfer tables is operatively projected, the other transfer table may be operatively retracted.

Also in this embodiment, whilst a pair of motor units are shown as employed, one for the projecting and retracting operations and the other for the rotations, it should be noted that anyone of the said bidirectional rotary link mechanisms X₁, X₂, X₃, X₄ and X₅ in the above seventh embodiment may be used as coupled to the drive shaft of each of the respective drive shafts of such first arms of the said pair of robotic link mechanisms. In this way, the distances of the operative projection and retraction as needed for operatively projecting and retracting the said transfer tables can be reduced.

While the present invention has hereinbefore been described with respect to certain illustrative embodiments thereof, it will readily be appreciated by a person skilled in the art to be obvious that many alterations thereof, omissions therefrom and additions thereto can be made without departing from the essence and the scope of the present invention. Accordingly, it should be understood that the present invention is not limited to the specific embodiments thereof set out above, but includes all possible embodiments thereof that can be made within the scope with respect to the features specifically set forth in the appended claims and encompasses all equivalents thereof. 

What is claimed is:
 1. A handling robot comprising: a plurality of coaxial bosses, wherein at least two of said bosses are capable of rotating independent of each other; a drive source connected to each of said plurality of bosses; a first robotic link mechanism including: a first pair of arms, each of said first pair of arms having a forward end and being connected to a separate one of said bosses; a first pair of links, each of said first pair of links having a forward end and a coupled end, said coupled end of each of said first pair of links being coupled to a respective forward end of said first pair of arms; and a first transfer table coupled to said forward end of each of said first pair of links, wherein said first robotic link mechanism is operable to project and retract said first transfer table in a radial direction with respect to said bosses; a second robotic link mechanism including: a second pair of arms, each of said second pair of arms having a forward end and being connected to a separate one of said bosses, wherein at least one of said second pair of arms is connected to one of said bosses having one of said first pair of arms connected thereto; a second pair of links, each of said second pair of links having a forward end and a coupled end, said coupled end of each of said second pair of links being coupled to a respective forward end of said second pair of arms; and a second transfer table coupled to said forward end of each of said second pair of links, wherein said second robotic link mechanism is operable to project and retract said second transfer table in a radial direction with respect to said bosses; and wherein said first robotic link mechanism and said second robotic link mechanism are capable of being jointly rotated, and wherein said first robotic link mechanism and said second robotic link mechanism are arranged such that an angular position of said first robotic link mechanism with respect to a circumference of said bosses is separated from an angular position of said second robotic link mechanism with respect to said circumference of said bosses.
 2. The robot of claim 1, wherein said angular position of said first robotic link mechanism is separated from said angular position of second robotic link mechanism by no more than 90 degrees with respect to said circumference of said bosses.
 3. The robot of claim 1, wherein said first transfer table and said second transfer table have an identical vertical position.
 4. The robot of claim 1, wherein said plurality of bosses comprises a first boss, a second boss, and a third boss, said first pair of arms including a first arm and a second arm, said second pair of arms including a third arm and a fourth arm, said first arm being connected to said first boss, said second arm and said third arm being connected to said second boss, and said fourth arm being connected to said third boss.
 5. The robot of claim 1, wherein said plurality of bosses comprises a first boss and a second boss, said first pair of arms including a first arm and a second arm, said second pair of arms including a third arm and a fourth arm, said first arm and said fourth arm being connected to said first boss, and said second arm and said third arm being connected to said second boss.
 6. The robot of claim 5, wherein said first arm and said fourth arm extend radially from a side surface of said first boss at diametrically opposite locations on said first boss, said second arm and said third arm extending radially in diametrically opposite directions with respect to said second boss, said second arm extending from a side surface of said second boss and said third arm extending from a vertical leg column located on a top surface of said second boss.
 7. The robot of claim 5, wherein said first arm and said fourth arm extend radially from a side surface of said first boss at diametrically opposite locations on said first boss, said second arm and said third arm extending radially from a side surface of said second boss at diametrically opposite locations on said second boss.
 8. A handling robot comprising: a plurality of coaxial bosses, wherein at least two of said bosses are capable of rotating independent of each other; a drive source connected to each of said plurality of bosses; a first robotic link mechanism including: a first pair of arms, each of said first pair of arms having a forward end and being connected to a separate one of said bosses; a first pair of links, each of said first pair of links having a forward end and a coupled end, said coupled end of each of said first pair of links being coupled to a respective forward end of said first pair of arms; and a first transfer table coupled to said forward end of each of said first pair of links, wherein said first robotic link mechanism is operable to project and retract said first transfer table in a radial direction with respect to said bosses; a second robotic link mechanism including: a second pair of arms, each of said second pair of arms having a forward end and being connected to a separate one of said bosses, wherein at least one of said second pair of arms is connected to one of said bosses having one of said first pair of arms connected thereto; a second pair of links, each of said second pair of links having a forward end and a coupled end, said coupled end of each of said second pair of links being coupled to a respective forward end of said second pair of arms; and a second transfer table coupled to said forward end of each of said second pair of links, wherein said second robotic link mechanism is operable to project and retract said second transfer table in a radial direction with respect to said bosses; and wherein said first robotic link mechanism and said second robotic link mechanism are capable of being jointly rotated, and wherein said plurality of bosses comprises a first boss, a second boss, and a third boss, said first pair of arms including a first arm and a second arm, said second pair of arms including a third arm and a fourth arm, said first arm being connected to said first boss, said second arm and said third arm being connected to said second boss, and said fourth arm being connected to said third boss.
 9. The robot of claim 8, wherein said first robotic link mechanism and said second robotic link mechanism are arranged such that one of said first transfer table and said second transfer table can be positioned above the other.
 10. The robot of claim 8, wherein said first arm extends radially from a side surface of said first boss, said second arm and said third arm extending radially from a side surface of said second boss at diametrically opposite locations on said second boss, and said fourth arm extending radially from a side surface of said third boss.
 11. The robot of claim 10, wherein said first robotic link mechanism and said second robotic link mechanism are arranged such that one of said first transfer table and said second transfer table can be positioned above the other.
 12. The robot of claim 10, wherein said first robotic link mechanism and said second robotic link mechanism are arranged such that an angular position of said first robotic link mechanism with respect to a circumference of said bosses is separated from an angular position of said second robotic link mechanism with respect to said circumference of said bosses.
 13. A handling robot comprising: a rotary table; a first drive source connected to said rotary table for rotating said rotary table; a first robotic link mechanism including: a first drive link mechanism having a forward end and a drive end and being supported by said rotary table so as to be capable of rotating; a first driven link mechanism having a forward end and a coupled end, said coupled end being coupled to said forward end of said first drive link mechanism such that said first driven link mechanism is capable of rotating in synchronism with a rotation of said first drive link mechanism; and a first transfer table coupled to said forward end of said first driven link mechanism, wherein said first robotic link mechanism is operable to project and retract said first transfer table in a radial direction with respect to said rotary table; a second robotic link mechanism including: a second drive link mechanism having a forward end and a drive end and being supported by said rotary table so as to be capable of rotating; a second driven link mechanism having a forward end and a coupled end, said coupled end being coupled to said forward end of said second drive link mechanism such that said second driven link mechanism is capable of rotating in synchronism with a rotation of said second drive link mechanism; and a second transfer table coupled to said forward end of said second driven link mechanism, wherein said second robotic link mechanism is operable to project and retract said second transfer table in a radial direction with respect to said rotary table; a second drive source connected to said drive end of said first drive link mechanism and said drive end of said second drive link mechanism for rotating said first drive link mechanism and said second drive link mechanism; and wherein said first robotic link mechanism and said second robotic link mechanism are capable of being jointly rotated, and wherein said first robotic link mechanism and said second robotic link mechanism are arranged such that an angular location of said first robotic link mechanism with respect to a circumference of said rotary table is separated from an angular position of said second robotic link mechanism with respect to said circumference of said rotary table.
 14. The robot of claim 13, wherein at least one of said first drive link mechanism, said first driven link mechanism, said second drive link mechanism, and said second driven link mechanism comprises a pair of parallel links.
 15. The robot of claim 13, wherein at least one of said first drive link mechanism, said first driven link mechanism, said second drive mechanism, and said second driven link mechanism comprises a belt mechanism.
 16. A handling robot comprising: a rotary table; a first drive source connected to said rotary table for rotating said rotary table; a first robotic link mechanism including: a first drive link mechanism having a forward end and a drive end and being supported by said rotary table so as to be capable of rotating; a first driven link mechanism having a forward end and a coupled end, said coupled end being coupled to said forward end of said first drive link mechanism such that said first driven link mechanism is capable of rotating in synchronism with a rotation of said first drive link mechanism; and a first transfer table coupled to said forward end of said first driven link mechanism, wherein said first robotic link mechanism is operable to project and retract said first transfer table in a radial direction with respect to said rotary table; a second robotic link mechanism including: a second drive link mechanism having a forward end and a drive end and being supported by said rotary table so as to be capable of rotating; a second driven link mechanism having a forward end and a coupled end, said coupled end being coupled to said forward end of said second drive link mechanism such that said second driven link mechanism is capable of rotating in synchronism with a rotation of said second drive link mechanism; and a second transfer table coupled to said forward end of said second driven link mechanism, wherein said second robotic link mechanism is operable to project and retract said second transfer table in a radial direction with respect to said rotary table; a second drive source connected to said drive end of said first drive link mechanism and said drive end of said second drive link mechanism for rotating said first drive link mechanism and said second drive link mechanism; and wherein said first robotic link mechanism and said second robotic link mechanism are capable of being jointly rotated, and wherein said first transfer table and said second transfer table have an identical vertical position. 